1.Evaluation of dose coverage to target volume and normal tissue sparing in the adjuvant radiotherapy of gastric cancers: 3D-CRT compared with dynamic IMRT
KK Murthy ; KA Shukeili ; SS Kumar ; CA Davis ; RR Chandran ; S Namrata
Biomedical Imaging and Intervention Journal 2010;6(3):1-7
Purpose: To assess the potential advantage of intensity-modulated radiotherapy (IMRT) over 3D-conformal
radiotherapy (3D-CRT) planning in postoperative adjuvant radiotherapy for patients with gastric carcinoma. Methods
and materials: In a retrospective study, for plan comparison, dose distribution was recalculated in 15 patients treated with 3D-CRT on the contoured structures of same CT images using an IMRT technique. 3D-conformal plans with three fields and four-fields were compared with seven-field dynamic IMRT plans. The different plans were compared by analyzing the dose coverage of planning target volume using TV95, Dmean, uniformity index, conformity index and homogeneity index parameters. To assess critical organ sparing, Dmean, Dmax, dose to one-third and two-third volumes of the OARs and percentage of volumes receiving more than their tolerance doses were compared. Results: The average dose coverage values of PTV with 3F-CRT and 4F-CRT plans were comparable, where as IMRT plans achieved better target coverage(p<0.001) with higher conformity index value of 0.81±0.07 compared to both the 3D-CRT plans. The doses to the liver and bowel reduced significantly (p<0.001) with IMRT plans compared to other 3D-CRT plans. For all OARs the percentage of volumes receiving more than their tolerance doses were reduced with the IMRT plans.
Conclusion: This study showed that a better target coverage and significant dose reduction to OARs could be achieved with the IMRT plans. The IMRT can be preferred with caution for organ motion. The authors are currently studying organ motion in the upper abdomen to use IMRT for patient treatment.
2.Preparation and characterization of prednisolone-poly (hydroxybutyrate-co-hydroxyvalerate) nanoparticles.
Jian-hai CHEN ; M SHAGUFTA ; S S DAVIS
Acta Pharmaceutica Sinica 2002;37(6):473-476
AIMTo optimize the preparation of sustained release prednisolone-poly (hydroxybutyrate-cohydroxyvalerate) (PNS-PHBV) nanospheres (NP) using the novel biodegradable materials PHBV as the carriers and PNS as a model drug.
METHODSPNS-PHBV nanospheres were prepared by ultrasonic-emulsion technique. The diameter, its distribution and Zeta potential on the surface of particles were measured by means of Zetasizer.
RESULTSThe diameter of NP is in the range of 50-250 nm. The drug loading of NP increases but incorporation efficiency and Zeta potential dramatically decrease with increasing ratio of the feeding quantities of drug to those of carriers. The drug release behavior in vitro appeared to have biphasic characteristics with initial burst effect. The more burst effect, the less the diameters of nanoparticles. The longest release time was up to 32 h.
CONCLUSIONThe technology of preparation is reasonable and PNS-PHBV nanoparticle showed significant sustained release.
Anti-Inflammatory Agents ; administration & dosage ; chemistry ; Delayed-Action Preparations ; Drug Carriers ; Hydroxybutyrates ; chemistry ; Nanotechnology ; Polyesters ; chemistry ; Polymers ; chemistry ; Prednisolone ; administration & dosage ; chemistry ; Technology, Pharmaceutical
3.Diagnostic accuracy of ultrasound for rotator cuff tears
Kelechi R OKOROHA ; Mohsin S FIDAI ; Joseph S TRAMER ; Kayla D DAVIS ; Patricia A KOLOWICH
Ultrasonography 2019;38(3):215-220
Ultrasonography (US) is an inexpensive, convenient, and effective tool that can be used to evaluate the shoulder. It does not expose the patient to harmful radiation and can be used to evaluate the musculoskeletal system dynamically. Additionally, US is not subject to metal artifacts when evaluating patients with previously placed hardware. Over the years, US has been found to be reliable and accurate for diagnosing rotator cuff tears (RCTs), despite its operator-dependence. The usage of US for diagnosing RCTs in orthopedic practice varies depending on practitioners' familiarity with the exam and the availability of experienced technicians. The purpose of this article is to review the diagnostic accuracy of US for identifying RCTs.
Artifacts
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Diagnostic Imaging
;
Humans
;
Musculoskeletal System
;
Orthopedics
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Recognition (Psychology)
;
Rotator Cuff
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Shoulder
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Tears
;
Ultrasonography
4.Spontaneous Spinal Epidural Hematoma: A Retrospective Study on Prognostic Factors and Review of the Literature.
Mark FEDOR ; Eric S KIM ; Kai DING ; J Paul MUIZELAAR ; Kee D KIM
Korean Journal of Spine 2011;8(4):272-282
OBJECTIVES: The spontaneous spinal epidural hematoma (SSEH) is a rare clinical entity. Patients typically present with sudden onset back pain followed by neurological deficits. METHODS: Diagnosis of SSEH is usually made with MRI and standard treatment is surgical evacuation. In 1996, Groen published the most comprehensive review on the SSEH in which he analyzed 333 cases. We review 104 cases of SSEH presented in the English literature since the last major review and add three of our own cases, for a total of 107 cases. RESULTS: Our patients presented with back pain and neurologic deficits. Two made excellent functional recovery with prompt surgical decompression while one continued to have significant deficits despite evacuation. Better postoperative outcome was associated with less initial neurological dysfunction, shorter time to operation from symptom onset and male patients. CONCLUSION: We discuss the etiology of SSEH and report current trends in diagnosis, treatment, and outcome.
Back Pain
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Decompression, Surgical
;
Hematoma, Epidural, Spinal
;
Humans
;
Male
;
Neurologic Manifestations
;
Retrospective Studies
5.Could fertility-sparing surgery be considered for women with early stage ovarian clear cell carcinoma?.
Dimitrios NASIOUDIS ; Eloise CHAPMAN-DAVIS ; Melissa K FREY ; Steven S WITKIN ; Kevin HOLCOMB
Journal of Gynecologic Oncology 2017;28(6):e71-
OBJECTIVE: The aim of the present retrospective population-based study was to investigate the oncologic impact of uterine and ovarian preservation (OP) in premenopausal women with stage IA or IC ovarian clear cell carcinoma (OCCC). METHODS: The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database was accessed and a cohort of surgically-staged premenopausal women (age <50 years) diagnosed with unilateral stage IA or IC OCCC was drawn. Based on site-specific surgery codes, women who did not undergo hysterectomy and/or bilateral salpingo-oophorectomy (BSO) were identified. Overall survival (OS) and cancer-specific survival (CSS) rates were calculated following generation of Kaplan-Meier curves; comparisons were made with the log-rank test. Multivariate Cox analysis was performed to control for possible confounders. RESULTS: A total of 741 premenopausal women who met the inclusion criteria were identified. Based on available information, rate of uterine preservation was 14.5% (96/663) while the rate of OP was 28.1% (71/253). Five-year CSS rates were 90.8% for women who did not undergo hysterectomy compared with 87.7% for those who did (p=0.290). Similarly, 5-year CSS rates in the OP and BSO groups were 92.6% and 85%, respectively (p=0.060). After controlling for disease sub-stage (IA vs. IC), uterine or OP was not associated with a worse overall or cancer-specific mortality. CONCLUSION: In the present cohort, uterine and OP did not have a negative impact on oncologic outcomes. Selection criteria for fertility-sparing surgery (FSS) could be expanded to include women with stage IA OCCC.
Adenocarcinoma, Clear Cell
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Cohort Studies
;
Epidemiology
;
Female
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Fertility
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Fertility Preservation
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Humans
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Hysterectomy
;
Mortality
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Ovarian Neoplasms
;
Patient Selection
;
Retrospective Studies
7.Consequences of chemotherapeutic agents on primordial follicles and future clinical applications
So Youn KIM ; Geum Joon CHO ; John S DAVIS
Obstetrics & Gynecology Science 2019;62(6):382-390
The ovarian reserve is necessary for female fertility and endocrine health. Commonly used cancer therapies diminish the ovarian reserve, thus, resulting in primary ovarian insufficiency, which clinically presents as infertility and endocrine dysfunction. Prepubertal children who have undergone cancer therapies often experience delayed puberty or cannot initiate puberty and require endocrine support to maintain a normal life. Thus, developing an effective intervention to prevent loss of the ovarian reserve is an unmet need for these cancer patients. The selection of adjuvant therapies to protect the ovarian reserve against cancer therapies underlies the mechanism of loss of primordial follicles (PFs). Several theories have been proposed to explain the loss of PFs. The “burn out” theory postulates that chemotherapeutic agents activate dormant PFs through an activation pathway. Another theory posits that chemotherapeutic agents destroy PFs through an “apoptotic pathway” due to high sensitivity to DNA damage. However, the mechanisms causing loss of the ovarian reserve remains largely speculative. Here, we review current literature in this area and consider the mechanisms of how gonadotoxic therapies deplete PFs in the ovarian reserve.
Adolescent
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Child
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DNA Damage
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Female
;
Fertility
;
Fertility Preservation
;
Humans
;
Infertility
;
Ovarian Follicle
;
Ovarian Reserve
;
Primary Ovarian Insufficiency
;
Puberty
;
Puberty, Delayed
8.Kinetic Evaluation of the Hypoxia Radiotracers 18 FFMISO and 18 F FAZA in Dogs with Spontaneous Tumors Using Dynamic PET/CT Imaging
Sangkyung CHOEN ; Michael S. KENT ; Abhijit J. CHAUDHARI ; Simon R. CHERRY ; Ana KRTOLICA ; Allison L. ZWINGENBERGER
Nuclear Medicine and Molecular Imaging 2023;57(1):16-25
Purpose:
We evaluated the kinetics of the hypoxia PET radiotracers, [18F]fluoromisonidazole ([18F]FMISO) and [18F] fluoroazomycin-arabinoside ([18F]FAZA), for tumor hypoxia detection and to assess the correlation of hypoxic kinetic parameters with static imaging measures in canine spontaneous tumors.
Methods:
Sixteen dogs with spontaneous tumors underwent a 150-min dynamic PET scan using either [18F]FMISO or [18F] FAZA. The maximum tumor-to-muscle ratio (TMR max ) > 1.4 on the last image frame was used as the standard threshold to determine tumor hypoxia. The tumor time-activity curves were analyzed using irreversible and reversible two-tissue compartment models and graphical methods. TMR max was compared with radiotracer trapping rate (k 3 ), influx rate (K i ), and distribution volume (V T ).
Results:
Tumor hypoxia was detected in 7/8 tumors in the [18F]FMISO group and 4/8 tumors in the [18F]FAZA group. All hypoxic tumors were detected at > 120 min with [18F]FMISO and at > 60 min with [18F]FAZA. [18F]FAZA showed better fit with the reversible model. TMR max was strongly correlated with the irreversible parameters (k3 and Ki ) for [18F]FMISO at > 90 min and with the reversible parameter (V T ) for [18F]FAZA at > 120 min.
Conclusions
Our results showed that [18F]FAZA provided a promising alternative radiotracer to [18F]FMISO with detecting the presence of tumor hypoxia at an earlier time (60 min), consistent with its favorable faster kinetics. The strong correlation betwee TMR max over the 90–150 min and 120–150 min timeframes with [18F]FMISO and [18F]FAZA, respectively, with kinetic parameters associated with tumor hypoxia for each radiotracer, suggests that a static scan measurement ( TMR max ) is a good alternative to quantify tumor hypoxia.
9.Immunogenicity and efficacy of Schmallenberg virus envelope glycoprotein subunit vaccines
Abaineh D ENDALEW ; Bonto FABURAY ; Jessie D TRUJILLO ; Natasha N GAUDREAULT ; A Sally DAVIS ; Vinay SHIVANNA ; Sun Young SUNWOO ; Wenjun MA ; Barbara S DROLET ; D Scott MCVEY ; Igor MOROZOV ; William C WILSON ; Juergen A RICHT
Journal of Veterinary Science 2019;20(6):e58-
The Schmallenberg virus (SBV) is an orthobunyavirus that causes abortions, stillbirths, and congenital defects in pregnant sheep and cattle. Inactivated or live attenuated vaccines have been developed in endemic countries, but there is still interest in the development of SBV vaccines that would allow Differentiating Infected from Vaccinated Animals (DIVA). Therefore, an attempt was made to develop novel DIVA-compatible SBV vaccines using SBV glycoproteins expressed in baculovirus. All vaccines and phosphate buffered saline (PBS) controls were prepared with adjuvant and administered subcutaneously to cattle at 6 month of age. The first trial included 2 groups of animals vaccinated with either carboxyl-terminus glycoprotein (Gc) or PBS and boosted after 2 weeks. In the second trial, 3 groups of cattle were administered either Gc, Gc and amino-terminus glycoprotein (Gn), or PBS with a booster vaccination after 3 weeks. The animals were challenged with SBV 9 days after the booster vaccination in the first study, and 3 weeks after the booster vaccination in the second study. Using a SBV Gc-specific enzyme-linked immunosorbent assay, antibodies were first detected in serum samples 14 days after the first vaccination in both trials, and peaked on days 7 and 9 after the booster in the first and second trials, respectively. Low titers of neutralizing antibodies were detected in serum from only 3/6 and 2/4 animals in the first and second trial, respectively, at 14 days after the first vaccination. The titers increased 2 to 3-fold after the booster vaccination. SBV-specific RNA was detected in the serum and selective tissues in all animals after SBV challenge independent of vaccination status. The SBV candidate vaccines neither prevented viremia nor conferred protection against SBV infection.
Animals
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Antibodies
;
Antibodies, Neutralizing
;
Baculoviridae
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Cattle
;
Congenital Abnormalities
;
Enzyme-Linked Immunosorbent Assay
;
Glycoproteins
;
Orthobunyavirus
;
RNA
;
Sheep
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Stillbirth
;
Vaccination
;
Vaccines
;
Vaccines, Attenuated
;
Vaccines, Subunit
;
Viremia
10.How the Commonwealth of the Northern Mariana Islands stalled COVID-19 for 22 months and managed its first significant community transmission
Dwayne Davis ; Stephanie Kern-Allely ; Lily Muldoon ; John M Tudela ; Jesse Tudela ; Renea Raho ; Heather S Pangelinan ; Halina Palacios ; John Tabaguel ; Alan Hinson ; Guillermo Lifoifoi ; Warren Villagomez ; Joseph R Fauver ; Haley L Cash ; Esther Muñ ; a ; Sean T Casey ; Ali S Khan
Western Pacific Surveillance and Response 2023;14(1):76-85
Objective: The Commonwealth of the Northern Mariana Islands (CNMI) is a remote Pacific island territory with a population of 47 329 that successfully prevented the significant introduction of coronavirus disease (COVID-19) until late 2021. This study documents how the response to the introduction of COVID-19 in CNMI in 2021 was conducted with limited resources without overwhelming local clinical capacity or compromising health service delivery for the population.
Methods: Data from COVID-19 case investigations, contact tracing, the Commonwealth’s immunization registry and whole genome sequencing were collated and analysed as part of this study.
Results: Between 26 March 2020 and 31 December 2021, 3281 cases and 14 deaths due to COVID-19 were reported in CNMI (case fatality rate, 0.4%). While notification rates were highest among younger age groups, hospitalization and mortality rates were disproportionately greater among those aged >50 years and among the unvaccinated. The first widespread community transmission in CNMI was detected in October 2021, with genomic epidemiology and contact tracing data indicating a single introduction event involving the AY.25 lineage and subsequent rapid community spread. Vaccination coverage was high before widespread transmission occurred in October 2021 and increased further over the study period.
Discussion: Robust preparedness and strong leadership generated resilience within the public health sector such that COVID-19 did not overwhelm CNMI’s health system as it did in other jurisdictions and countries around the world. At no point was hospital capacity exceeded, and all patients received adequate care without the need for health-care rationing.