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1.
MAGMA ; 36(6): 933-943, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37566311

RESUMEN

OBJECTIVE: To enhance RF safety when implantable medical devices are located within the body coil but outside the imaging region by using a secondary resonator (SR) to reduce electric fields, the corresponding specific absorption rate (SAR), and temperature change during MRI. MATERIALS AND METHODS: This study was conducted using numerical simulations with an American Society for Testing and Materials (ASTM) phantom and adult human models of Ella and Duke from Virtual Family Models, along with corresponding experimental results of temperature change obtained using the ASTM phantom. The circular SR was designed with an inner diameter of 150 mm and a width of 6 mm. Experimental measurements were carried out using a 3 T Medical Implant Test System (MITS) body coil, electromagnetic (EM) field mapping probes, and an ASTM phantom. RESULTS: The magnitudes of B1+ (|B1+|) and SAR1g were reduced by 15.2% and 5.85% within the volume of interest (VoI) of an ASTM phantom, when a SR that generates opposing electromagnetic fields was utilized. Likewise, the Δ|B1+| and ΔSAR1g were reduced by up to 56.7% and 57.5% within the VoI of an Ella model containing a copper rod when an opposing SR was used. CONCLUSION: A novel method employing the designed SR, which generates opposing magnetic fields to partially shield a sample, has been proposed to mitigate the risk of induced-RF heating at the VoI through numerical simulations and corresponding experiments under various conditions at 3.0 T.


Asunto(s)
Campos Electromagnéticos , Prótesis e Implantes , Humanos , Campos Magnéticos , Fantasmas de Imagen , Imagen por Resonancia Magnética/métodos , Ondas de Radio
2.
Magn Reson Med ; 87(3): 1515-1528, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34775615

RESUMEN

PURPOSE: There is increasing use of open-bore vertical MR systems that consist of two planar RF coils. A recent study showed that the RF-induced heating of a neuromodulation device was much lower in the open-bore system at the brain and the chest imaging landmarks. This study focused on the hip and knee implants and compared the specific absorption rate (SAR) distribution in human models in a 1.2T open-bore coil with that of a 1.5T conventional birdcage coil. METHODS: Computational modeling results were compared against the measurement values using a saline phantom. The differences in RF exposure were examined between a 1.2T open-bore coil and a 1.5T conventional birdcage coil using SAR in an anatomical human model. RESULTS: Modeling setups were validated. The body placed closed to the coil elements led to high SAR values in the birdcage system compared with the open-bore system. CONCLUSION: Our computational modeling showed that the 1.2T planar system demonstrated a lower intensity of SAR distribution adjacent to hip and knee implants compared with the 1.5T conventional birdcage system.


Asunto(s)
Imagen por Resonancia Magnética , Ondas de Radio , Calefacción , Humanos , Fantasmas de Imagen , Prótesis e Implantes
3.
MAGMA ; 33(5): 725-733, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31980963

RESUMEN

OBJECTIVE: To improve sensitivity and uniformity of MR images obtained using a phased array RF coil, an inductively coupled secondary resonator with RF detuning circuits at 300 MHz was designed. MATERIALS AND METHODS: A secondary resonator having detuning circuits to turn off the resonator during the transmit mode was constructed. The secondary resonator was located at the opposite side of the four-channel phased array to improve sensitivity and uniformity of the acquired MR images. Numerical simulations along with phantom and in vivo experiments were conducted to evaluate the designed secondary resonator. RESULTS: The numerical simulation results of |B1+| in a transmit mode showed that magnetic field uniformity would be decreased with a secondary resonator having no detuning circuits because of unwanted interferences between the transmit birdcage coil and the secondary resonator. The standard deviation (SD) of |B1+| was decreased 57% with a secondary resonator containing detuning circuits. The sensitivity and uniformity of |B1-| in the receive mode using a four-channel phased array were improved with the secondary resonator. Phantom experiments using a uniform saline phantom had 20% improvement of the mean signal intensity and 50% decrease in the SD with the secondary resonator. Mice with excess adipose tissue were imaged to demonstrate the utility of the secondary resonator. CONCLUSION: The designed secondary resonator having detuning circuits improved sensitivity and uniformity of mouse MR images acquired using the four-channel phased array.


Asunto(s)
Imagen por Resonancia Magnética , Ondas de Radio , Animales , Diseño de Equipo , Campos Magnéticos , Ratones , Fantasmas de Imagen
4.
MAGMA ; 32(1): 15-23, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29948237

RESUMEN

OBJECTIVE: Improve 19F magnetic resonance imaging uniformity of perfluorocarbon (PFC)-labeled cells by using a secondary inductive resonator tuned to 287 MHz to enhance the induced radio frequency (RF) magnetic field (B1) at 7.05 T. MATERIALS AND METHODS: Following Faraday's induction law, the sign of induced B1 made by the secondary resonator can be changed depending on the tuning of the resonator. A secondary resonator located on the opposite side of the phantom of the 19F surface coil can be shown to enhance or subtract the induced B1 field, depending upon its tuning. RESULTS: The numerical simulation results of rotating transmit B1 magnitude (|B 1 + |) and corresponding experimental 19F images were compared without and with the secondary resonator. With the secondary resonator tuned to 287 MHz, improvements of |B 1 + | and 19F image uniformity were demonstrated. The use of the secondary resonator improved our ability to visualize transplanted cell location non-invasively over a period of 6 weeks. CONCLUSION: The secondary resonator tuned to enhance the induced B1 results in improved image uniformity in a pre-clinical application, enabling cell tracking of PFC-labeled cells with the secondary resonator.


Asunto(s)
Rastreo Celular/métodos , Imagen por Resonancia Magnética con Fluor-19 , Flúor/química , Campos Magnéticos , Trasplante de Células Madre , Animales , Diseño de Equipo , Fluorocarburos , Ratones , Modelos Teóricos , Fantasmas de Imagen , Ondas de Radio , Relación Señal-Ruido
5.
BJOG ; 125(2): 131-138, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28139875

RESUMEN

OBJECTIVE: We sought to classify causes of stillbirth for six low-middle-income countries using a prospectively defined algorithm. DESIGN: Prospective, observational study. SETTING: Communities in India, Pakistan, Guatemala, Democratic Republic of Congo, Zambia and Kenya. POPULATION: Pregnant women residing in defined study regions. METHODS: Basic data regarding conditions present during pregnancy and delivery were collected. Using these data, a computer-based hierarchal algorithm assigned cause of stillbirth. Causes included birth trauma, congenital anomaly, infection, asphyxia, and preterm birth, based on existing cause of death classifications and included contributing maternal conditions. MAIN OUTCOME MEASURES: Primary cause of stillbirth. RESULTS: Of 109 911 women who were enrolled and delivered (99% of those screened in pregnancy), 2847 had a stillbirth (a rate of 27.2 per 1000 births). Asphyxia was the cause of 46.6% of the stillbirths, followed by infection (20.8%), congenital anomalies (8.4%) and prematurity (6.6%). Among those caused by asphyxia, 38% had prolonged or obstructed labour, 19% antepartum haemorrhage and 18% pre-eclampsia/eclampsia. About two-thirds (67.4%) of the stillbirths did not have signs of maceration. CONCLUSIONS: Our algorithm determined cause of stillbirth from basic data obtained from lay-health providers. The major cause of stillbirth was fetal asphyxia associated with prolonged or obstructed labour, pre-eclampsia and antepartum haemorrhage. In the African sites, infection also was an important contributor to stillbirth. Using this algorithm, we documented cause of stillbirth and its trends to inform public health programs, using consistency, transparency, and comparability across time or regions with minimal burden on the healthcare system. TWEETABLE ABSTRACT: Major causes of stillbirth are asphyxia, pre-eclampsia and haemorrhage. Infections are important in Africa.


Asunto(s)
Algoritmos , Sistema de Registros , Mortinato/epidemiología , África/epidemiología , Asia/epidemiología , Países en Desarrollo , Femenino , Salud Global , Guatemala/epidemiología , Humanos , Servicios de Salud Materno-Infantil , Embarazo , Complicaciones del Embarazo/epidemiología , Estudios Prospectivos
6.
IEEE Trans Electromagn Compat ; 59(5): 1382-1389, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29456259

RESUMEN

This study investigates the use of pads with high dielectric constant (HDC) materials to alter electromagnetic field distributions in patients during magnetic resonance imaging (MRI). The study was performed with numerical simulations and phantom measurements. An initial proof-of-concept and validation was performed using a phantom at 64 MHz, showing increases of up to 10% in electromagnetic field when using distilled water as the high dielectric material. Additionally, numerical simulations with computational models of human anatomy were performed at 128 MHz. Results of these simulations using barium titanate (BaTiO3) beads showed a 61% increase of [Formula: see text] with a quadrature driven RF coil and a 64% increase with a dual-transmit array. The presence of the HDC material also allowed for a decrease of SAR up to twofold (e.g., peak 10 g-averaged SAR from 54 to 22 W/kg with a quadrature driven RF coil and from 27 to 22 W/kg with a dual-transmit array using CaTiO3 powder at 128 MHz). The results of this study show that the use of HDC pads at 128 MHz for MRI spine applications could result in improved magnetic fields within the region of interest, while decreasing SAR outside the region.

7.
IEEE Trans Electromagn Compat ; 59(5): 1390-1399, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29456260

RESUMEN

This study describes the MRI-related radio frequency (RF) safety evaluation of breast tissue expander devices to establish safety criteria. Numerical simulations and experimental measurements were performed at 64 MHz with a gel phantom containing a breast expander. Additionally, computational modeling was performed (64 and 128 MHz) with an adult female model, containing a virtually implanted breast tissue expander device for four imaging landmark positions. The presence of the breast tissue expander device led to significant alterations in specific absorption rate (SAR) and|B1+|distributions. The main source of SAR alterations with the use of the breast expander device was the saline-filled pouch of the expander. Conversely, the variation of RF magnetic field (B1+) was mainly caused by the metallic port. The measured values of electric field magnitude did not increase significantly due to the introduction of the expander device. The maximum 1g- or 10g-averaged SAR values in tissues near the implant were lower than those expected in other regions of the patient body with normalization of both|B1+|equal to 2 µT at the coil isocenter and whole body averaged SAR equal to 4W/kg.

9.
Pathol Biol (Paris) ; 63(2): 69-73, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25596173

RESUMEN

Investigations of the etiologic agents of community-acquired acute respiratory illness may lead to better treatment decisions and patient outcomes. In a routine care setting, we assessed the diagnostic performance of a multiplex PCR assay with respect to conventional microbiological methods, in a continuous series of adult cases of community-acquired acute respiratory illness. We enrolled 279 adult patients hospitalised for community-acquired acute respiratory illness at Tours University Hospital during the winter of 2011-2012. Respiratory samples (mostly nasopharyngeal aspirates) were studied prospectively by indirect immunofluorescence assay and multiplex PCR, that enable detection of 8 viruses and 21 respiratory pathogens respectively. In total, 255 of the 279 (91.4%) samples had interpretable results by both methods. At least one respiratory pathogen was detected by multiplex PCR in 171 specimens (65%). Overall, 130 (76%) of the 171 positive samples were positive for only one respiratory pathogen, 37 (22%) samples were positive for two pathogens and four (2%) were positive for three pathogens. With indirect immunofluorescence assay, a respiratory virus was detected in 27 of the 255 (11%) specimens. Indirect immunofluorescence assay detected some of the influenza virus A (15/51, 29%) infections identified by multiplex PCR and some (7/15, 47%) human metapneumovirus and (5/12, 42%) respiratory syncytial virus infections, but it did not detect all the adenovirus infections. Thus, access to multiplex molecular assays improves the diagnostic spectrum and accuracy over conventional methods, increasing the frequency of identification of the respiratory pathogens involved in community-acquired acute respiratory illness.


Asunto(s)
Infecciones Comunitarias Adquiridas/diagnóstico , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Infecciones del Sistema Respiratorio/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/genética , Infecciones Comunitarias Adquiridas/microbiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/genética , Infecciones del Sistema Respiratorio/microbiología , Adulto Joven
10.
Prog Urol ; 23(15): 1327-41, 2013 Nov.
Artículo en Francés | MEDLINE | ID: mdl-24183091

RESUMEN

OBJECTIVE: To define prescription modalities for the use of antibiotics in urology. METHODS: A bibliographic research was performed using the MEDLINE database concerning all the antibiotics usable in urology. Treatments were classified by families; modes of action, indications in urology and adverse events have been detailed. Administrative files for commercial use have been consulted and associated with literature analysis. RESULTS: About 8 classes of antibiotics are usable in urology in a routine use. How they work, indications in urology and adverse events are discussed. CONCLUSION: Knowing that bacterial resistance to quinilones is increasing dramatically, it seems imperative to control the use of 8 classes of antibiotics.


Asunto(s)
Antibacterianos/uso terapéutico , Infecciones Urinarias/tratamiento farmacológico , Fosfomicina/uso terapéutico , Glicopéptidos/uso terapéutico , Humanos , Nitrofuranos/uso terapéutico , Paromomicina/uso terapéutico , Quinolonas/uso terapéutico , Tetraciclinas/uso terapéutico , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Infecciones Urinarias/microbiología , beta-Lactamas/uso terapéutico
11.
J Pharm Bioallied Sci ; 15(Suppl 1): S333-S335, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37654277

RESUMEN

The present study aimed to evaluate the peri-implant tissue response and marginal bone levels of immediately loaded narrow diameter dental implants. In this study, 10 patients with single maxillary anterior edentulous space were included. Implants were placed and immediate provisional crown was given without any centric or eccentric contacts. After three months, a definitive restoration was placed. All the clinical and radiographical parameters were evaluated.

12.
Natl Med J India ; 25(4): 207-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23278777

RESUMEN

BACKGROUND: In July 2010, we started universal individual donor nucleic acid testing (ID-NAT) at our blood bank. This test simultaneously detects human immunodeficiency virus-1 (HIV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV) in samples of donor blood. We continued to do the enzymelinked immunosorbent assay (ELISA) test for these agents, as per the guidelines of the Drug Controller General of India. We assessed the impact of ID-NAT in preventing transfusionassociated transmission of viruses. METHODS: We used fourth generation ELISA to screen blood samples of all voluntary and replacement blood donors. ID-NAT was done by transcription-mediated amplification (TMA). RESULTS: Of the 18 356 donors, ID-NAT could not be performed on 2 samples which were inadequate. Of the 18 354 donors tested by both ID-NAT and fourth generation ELISA, 7 were found to be NAT-positive but ELISA-negative (NAT yield) for HBV and HCV. The prevalence of NAT yield cases among routine donors was 1 in 2622 donations tested (0.038%). Since we supply blood as components (packed red cells, fresh frozen plasma and platelet concentrate), these 7 units of blood would have yielded 21 components and hence 21 patients could have been infected with HBV and HCV viruses. CONCLUSION: In the vast majority of blood units tested, the results of ELISA and ID-NAT for HIV-1, HBV and HCV were concordant. ID-NAT did detect the presence of viruses missed by ELISA in some blood units. It widespread use in blood banks would ensure safer blood transfusion.


Asunto(s)
Bancos de Sangre/normas , ADN Viral/sangre , VIH-1/aislamiento & purificación , Hepacivirus/aislamiento & purificación , Virus de la Hepatitis B/aislamiento & purificación , ARN Viral/sangre , Centros de Atención Terciaria/normas , Adolescente , Adulto , Donantes de Sangre , Recolección de Muestras de Sangre , VIH-1/genética , Hepacivirus/genética , Virus de la Hepatitis B/genética , Humanos , Persona de Mediana Edad , Adulto Joven
13.
J Orthop Case Rep ; 11(7): 12-15, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34790594

RESUMEN

INTRODUCTION: When the fracture fails to heal for more than 12 months, it is called chronic non-union. Surgical intervention becomes mandatory to get this type of fracture healed. We are reporting our results in a case of congenital pseudoarthrosis of the tibia (CPT) having chronic non-union of 18 years duration with superadded infection following attempted surgery, using Ilizarov technology. We shall highlight the problems found during the course of treatment and different strategies to tackle them. CASE PRESENTATION: An 18-year-old female, born with CPT of the right tibia with neurofibromatosis, presented as Type 1 infected non-union following three unsuccessful surgeries. She had neurofibromatic nodules all over the body including the face. The leg had multiple active draining sinuses, with evidence of healed sinuses and operating scars, adherent to underlying bone. She had 20 cm of limb shortening. Prolonged morbidity made her socially isolated. Being poor, they could not manage her medical expenses. They started believing that amputation would be a viable option and with that feeling in mind, they approached us. After few sittings of counseling, they somehow agreed to give it a try. After preparing the patient, a radical excision of the infected and dead tissue was done. A 3 ring Ilizarov assembly was mounted as the distal fragment was very small. A corticotomy was done to fill up 10 cm of gap following excision and subsequent limb lengthening. She developed hyporegenerate, pin-tract infections (PTIs) during the course of treatment which were tackled accordingly. She also developed psychological problems due to nature of treatment that was taken care of too. The fracture united and she could start walking unaided. There was no recurrence of infection. The ring was kept in situ for about 700 days. CONCLUSION: Chronic non-union associated with neurofibromatosis and infection is a very challenging situation. Radical debridement is the key to prevent recurrence of both. Ilizarov system plays the most significant role in forming regenerate by distraction. Hyporegenerate and PTIs could be tackled meticulously to prevent complications and attain the desired result. The patient could achieve painless unaided walking after the treatment. Probably instilling self-confidence in the patient was one of the most important aspects to sustain such an arduous journey.

14.
J Physiol Pharmacol ; 72(5)2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-35288478

RESUMEN

Betaine is a biologically active compound exerting beneficial effects in the organism, however, the exact mechanisms underlying its action are not fully elucidated. The present study aimed to explore, whether betaine alleviates disorders induced by feeding rats a high-fat diet (HFD). Rats were divided into 3 groups: control, fed an HFD and fed an HFD and receiving betaine (2% water solution for 8 weeks). Betaine improved glucose tolerance, decreased blood levels of non-esterified fatty acids and prevented lipid accumulation in the skeletal muscle of rats on an HFD. Betaine reduced activities of blood alanine aminotransferase, blood levels of bilirubin and hepatic lipid content. Expression of fatty acid synthase in the liver and the skeletal muscle was decreased in response to feeding an HFD, and this effect was deepened by betaine in the muscle tissue. Hepatic and muscular expression of genes related to insulin signaling were unchanged in HFD-fed rats. Lipolysis stimulated by epinephrine (an adrenergic receptor agonist), forskolin (an activator of adenylate cyclase), dibutyryl-cAMP (an activator of protein kinase A) and DPCPX (an adenosine A1 receptor antagonist) was diminished in the adipocytes of rats fed an HFD, however, this effect was alleviated by betaine. Moreover, blood leptin levels in HFD-fed rats were elevated, whereas leptinemia have normalized by betaine supplementation. Betaine prevented the increase in expression of N-methyl D-aspartate receptors in the hippocampus and in the cerebral cortex. These results indicate that betaine positively affects the insulin-sensitive tissues: liver (hepatoprotective effects), skeletal muscle (reduced lipid accumulation) and adipose tissue (a rise in lipolysis), which is associated with improved insulin sensitivity. Betaine-induced prevention of hyperleptinemia indicates restoration of leptin action, and changes in the brain reveal neuroprotective properties. Our results show that betaine induces positive changes in HFD-fed rats, its action is pleiotropic and involves different tissues.


Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Animales , Betaína/farmacología , Betaína/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Dieta Alta en Grasa/efectos adversos , Suplementos Dietéticos , Resistencia a la Insulina/fisiología , Ratas
15.
Malays Orthop J ; 14(2): 47-56, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32983377

RESUMEN

INTRODUCTION: A gap non-union in various conditions has been treated successfully by the Ilizarov method. The gap can be filled up either by an acute shortening and re-lengthening (ASRL) procedure or by an internal bone transport (IBT). We compared the functional and clinical outcome of ASRL and IBT in gap non-unions of the infected tibia. MATERIAL AND METHODS: A retrospective study was conducted in our department from the data collected in the period between 1997 and 2010. There were 86 cases of infected non-union of the tibia, in patients of the age group 18 to 65 years, with a minimum two-year follow-up. Group A consisted of cases treated by ASRL (n=46), and Group B, of cases by IBT (n=40). The non-union following both open and closed fractures had been treated by plate osteosynthesis, intra-medullary nails and primary Ilizarov fixators. Radical debridement was done and fragments stabilised with ring fixators. The actual bone gap and limb length discrepancy were measured on the operating table after debridement. In ASRL acute docking was done for defects up to 3cm, and subacute docking for bigger gaps. Corticotomy was done once there was no infection and distraction started after a latency of seven days. Dynamisation was followed by the application of a patellar tendon bearing cast for one month after removal of the ring with the clinico-radiological union. RESULTS: The bone loss was 3 to 8cm (4.77±1.43) in Group A and 3 to 9cm (5.31± 1.28) in Group B after thorough debridement. Bony union, eradication of infection and primary soft- tissue healing was 100%, 85% and 78% in Group A and 95%, 60%, 36% in Group B respectively. Nonunion at docking site, equinus deformity, false aneurysm, interposition of soft-tissue, transient nerve palsies were seen only in cases treated by IBT. CONCLUSION: IBT is an established method to manage gap non-union of the tibia. In our study, complications were significantly higher in cases where IBT was employed. We, therefore, recommend ASRL with an established protocol for better results in terms of significantly less lengthening index, eradication of infection, and primary soft tissue healing. ASRL is a useful method to bridge the bone gap by making soft tissue and bone reconstruction easier, eliminating the disadvantages of IBT.

16.
J Clin Microbiol ; 47(4): 1249-51, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19171683

RESUMEN

Human-to-human transmission of Mycobacterium bovis in two immunocompetent patients from the same family was confirmed by spoligotyping (pattern F35, which was only observed in cattle from the same area in France). A single allelic difference between animal and human isolates was observed with mycobacterial interspersed repetitive units containing variable-number tandem repeats, suggesting a jump across the species barrier.


Asunto(s)
Mycobacterium bovis/clasificación , Mycobacterium bovis/aislamiento & purificación , Tuberculosis/microbiología , Tuberculosis/transmisión , Adulto , Animales , Técnicas de Tipificación Bacteriana , Bovinos , Dermatoglifia del ADN , ADN Bacteriano/genética , Salud de la Familia , Femenino , Francia , Genotipo , Humanos , Secuencias Repetitivas Esparcidas , Masculino , Persona de Mediana Edad , Repeticiones de Minisatélite , Mycobacterium bovis/genética , Adulto Joven
17.
Genetika ; 45(7): 941-8, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19705746

RESUMEN

In this study, 25 heterologous bovine microsatellite markers have been used for the assessment of genetic diversity in Nagpuri buffalo, an important breed of Central India. For this, 48 DNA samples of unrelated individuals of Nagpuri buffalo were PCR amplified and microsatellite alleles were resolved in 6% denaturing, silver stained Urea-PAGE gel. Genotypic status of individuals at each locus was identified manually and data analysis carried out using POPGENE software. Observed number of alleles varied from 2 (ILSTS073 locus) to 8 (HEL13 & ILSTS058 loci) with a mean of 5.24 alleles per locus. Moderate level of heterozygosity (0.45) indicated sufficient genetic diversity existing in this buffalo population. PIC values for the microsatellite loci analysed, ranged from 0.10 (ILSTS019 locus) to 0.81 (ILSTS058 locus) with a mean of 0.53. No shift in the frequency distribution of alleles and a normal L-shaped curve indicated non-existence of any bottleneck in Nagpuri. The study thus highlights the usefulness of heterologous bovine microsatellite markers to assess the genetic variability in buffalo breeds as well. Also various diversity indices suggest sufficient genetic variability within Nagpuri buffalo that can be utilized as initial guidelines for future breeding strategies and conservation.


Asunto(s)
Búfalos/genética , Variación Genética , Genética de Población , Animales , Cruzamiento , India , Repeticiones de Microsatélite
18.
PLoS One ; 14(10): e0223857, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31652280

RESUMEN

OBJECTIVES: We assessed the determinants of mortality in infective endocarditis (IE), using the national hospital discharge databases (HDD) in 2011. METHODS: IE stays were extracted from the national HDD, with a definition based on IE-related diagnosis codes. This definition has been assessed according to Duke criteria by checking a sample of medical charts of IE giving a predictive positive value of 86.1% (95% confidence interval (CI): 82.7% - 89.5%). The impact of heart valve surgery on survival has been studied if performed during the initial stay, and over the year of follow-up. Risk factors of in-hospital mortality were identified using logistic regression model for the initial stay and Cox Time-dependent model for the 1-year mortality. RESULTS: The analysis included 6,235 patients. The annual incidence of definite IEs was 63 cases/million residents. Staphylococci and Streptococci were the most common bacteria (44% and 45%, respectively). A valvular surgery was performed in 20% of cases, but substantial variations existed between hospitals. The in-hospital mortality was 21% (ranging 12% to 27% according to the region of patients), associated with age>70, chronic liver disease, renal failure, S. aureus, P. aeruginosa or candida infection and strokes whereas valvular surgery, a native valve IE or intraveinous drug use (right heart IE) were significantly protective for an initial death. The same factors were associated with the one-year mortality, except for valvular surgery which was associated with a 1.4-fold higher risk of death during the year post IE. CONCLUSION: We reported a high IE incidence rate. Valvular surgery was considerably less frequent in this study than in the previous published data (near 50%) whereas mortality was similar. Surgery was associated with higher survival if undergone within the initial stay. There were significant regional differences in frequency of surgery but it did not impact mortality.


Asunto(s)
Endocarditis/microbiología , Válvulas Cardíacas/cirugía , Alta del Paciente/estadística & datos numéricos , Infecciones Estafilocócicas/mortalidad , Infecciones Estreptocócicas/mortalidad , Anciano , Anciano de 80 o más Años , Endocarditis/mortalidad , Femenino , Francia/epidemiología , Válvulas Cardíacas/microbiología , Mortalidad Hospitalaria , Humanos , Incidencia , Estimación de Kaplan-Meier , Tiempo de Internación , Modelos Logísticos , Masculino , Persona de Mediana Edad , Mortalidad , Estudios Retrospectivos , Infecciones Estafilocócicas/epidemiología , Infecciones Estreptocócicas/epidemiología
19.
Neoplasia ; 21(1): 1-16, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30472500

RESUMEN

This white paper discusses prospects for advancing hyperpolarization technology to better understand cancer metabolism, identify current obstacles to HP (hyperpolarized) 13C magnetic resonance imaging's (MRI's) widespread clinical use, and provide recommendations for overcoming them. Since the publication of the first NIH white paper on hyperpolarized 13C MRI in 2011, preclinical studies involving [1-13C]pyruvate as well a number of other 13C labeled metabolic substrates have demonstrated this technology's capacity to provide unique metabolic information. A dose-ranging study of HP [1-13C]pyruvate in patients with prostate cancer established safety and feasibility of this technique. Additional studies are ongoing in prostate, brain, breast, liver, cervical, and ovarian cancer. Technology for generating and delivering hyperpolarized agents has evolved, and new MR data acquisition sequences and improved MRI hardware have been developed. It will be important to continue investigation and development of existing and new probes in animal models. Improved polarization technology, efficient radiofrequency coils, and reliable pulse sequences are all important objectives to enable exploration of the technology in healthy control subjects and patient populations. It will be critical to determine how HP 13C MRI might fill existing needs in current clinical research and practice, and complement existing metabolic imaging modalities. Financial sponsorship and integration of academia, industry, and government efforts will be important factors in translating the technology for clinical research in oncology. This white paper is intended to provide recommendations with this goal in mind.


Asunto(s)
Isótopos de Carbono , Imagen por Resonancia Magnética/métodos , Neoplasias/diagnóstico , Animales , Modelos Animales de Enfermedad , Humanos , Reproducibilidad de los Resultados , Investigación Biomédica Traslacional
20.
Front Physiol ; 9: 1439, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30459628

RESUMEN

Purpose: The purpose of this study was to investigate the need for high-resolution detailed anatomical modeling to correctly estimate radio-frequency (RF) safety during magnetic resonance imaging (MRI). RF-induced heating near metallic implanted devices depends on the electric field tangential to the device (Etan ). Etan and specific absorption rate (SAR) were analyzed in blood vessels of an anatomical model to understand if a standard gel phantom accurately represents the potential heating in tissues due to passive vascular implants such as stents. Methods: A numerical model of an RF birdcage body coil and an anatomically realistic virtual patient with a native spatial resolution of 1 mm3 were used to simulate the in vivo electric field at 64 MHz (1.5 T MRI system). Maximum values of SAR inside the blood vessels were calculated and compared with peaks in a numerical model of the ASTM gel phantom to see if the results from the simplified and homogeneous gel phantom were comparable to the results from the anatomical model. Etan values were also calculated in selected stent trajectories inside blood vessels and compared with the ASTM result. Results: Peak SAR values in blood vessels were up to ten times higher than those found in the ASTM standard gel phantom. Peaks were found in clinically significant anatomical locations, where stents are implanted as per intended use. Furthermore, Etan results showed that volume-averaged SAR values might not be sufficient to assess RF safety. Conclusion: Computational modeling with a high-resolution anatomical model indicated higher values of the incident electric field compared to the standard testing approach. Further investigation will help develop a robust safety testing method which reflects clinically realistic conditions.

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