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The present study was designed to characterize phenotypically and genotypically a Trueperella (T.) pecoris strain isolated from necrotic vestibulitis of a 10-year-old camel (Camelus dromedarius). The species identity of T. pecoris 203/7 investigated in the present study could be confirmed by phenotypic properties and by phylogenetic analyses based on partial sequencing of the 16S ribosomal RNA (rRNA) gene, the 16S-23S rDNA intergenic spacer region, the glyceraldehyde 3-phosphate dehydrogenase encoding gene gap, elongation factor Tu encoding gene tuf and the target gene rpoB encoding the ß-subunit of bacterial RNA polymerase. T. pecoris strain 203/7 was grouped within the genus Trueperella in the family Arcanobacteriaceae. The 16S rRNA gene analysis showed a sequence identity of 99·9% to reference strain T. pecoris DSM 111392T . The present isolate was clearly identified as T. pecoris, the most recently described species of the genus Trueperella. Strain T. pecoris 203/7 was isolated in moderate numbers from necrotic vestibulitis of the camel and could be of some importance for the infectious process. However, the investigated strain represents the first isolation of T. pecoris from a camel.
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Camelus , Animales , Camelus/genética , ADN Bacteriano/genética , ADN Intergénico , ADN Ribosómico/genética , Genotipo , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADNRESUMEN
Regulation of crucial lncRNAs involved in differentiation of chicken embryonic stem cells (ESCs) to spermatogonia stem cells (SSCs) was explored by sequencing the transcriptome of ESCs, primordial germ cells (PGCs) and SSCs with RNA-Seq; analytical bioinformatic methods were used to excavate candidate lncRNAs. We detected expression of candidate lncRNAs in ESCs, PGCs and SSCs and forecasted related target genes. Utilizing wego, david and string, function and protein-protein interactions of target genes were analyzed. Finally, based on string analysis, interaction diagrams and relevant signaling pathways were established. Our results indicate a total of 9657 lncRNAs in ESCs, PGCs and SSCs, with 3549 defined as significantly different. We screened 20 candidate lncRNAs, each demonstrating a greater than eight-fold difference in |logFC| value between groups (ESCs vs. PGCs, ESCs vs. SSCs and PGCs vs. SSCs) or specifically expressed in an individual cell type. qRT-PCR results indicated that expression tendencies of candidate lncRNAs were consistent with RNA-Seq. Fifteen cis and four trans target genes were forecasted. Based on wego and string analyses, we found lnc-SSC1, lnc-SSC5, lnc-SSC2 and lnc-ESC2 negatively regulated target genes SUFU, EPHA3, KLF3, ARL3 and TRIM8, whereas SHH, NOTCH, TGF-ß, cAMP/cGMP and JAK/STAT signaling pathways were promoted, causing differentiation of ESCs into SSCs. Our findings represent a preliminary unveiling of lncRNA-associated regulatory mechanisms during differentiation of chicken ESCs into SSCs, filling a research void in male germ cell differentiation related to lncRNA. Our results also provide basic information for improving in vitro induction systems for differentiation of chicken ESCs into SSCs.
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Células Madre Germinales Adultas/citología , Diferenciación Celular , Embrión de Pollo/citología , ARN Largo no Codificante/análisis , ARN Largo no Codificante/metabolismo , Transducción de Señal , Animales , Embrión de Pollo/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ARNRESUMEN
The aim of the present study was to examine possible effects of a different protein supply on the presence of Campylobacter in excreta and caecal content of broiler chickens. Therefore, 220 one-day-old chickens were fed five different diets in the experimental period (day 8 onwards). In the control group (CON; n = 3 boxes), a soya bean-based industrially produced complete diet containing 5-10% whole wheat and coccidiostats was fed, whereas in the remaining groups, four own-made complete diets with four protein sources and combinations (4 × 2 boxes; soya bean meal-based diet = SBM; rapeseed meal-containing diet = RSM; haemoglobin meal-containing diet = HGP; algae-containing diet = ALG) were offered. During the 6-week trial period, data concerning performance parameters, excreta and litter characteristics and microbiological analysis of excreta and caecal content at dissection were collected. The qualitative bacteriological investigation was based on the EN ISO 10272-1:2006, taken from the official collection of analysis methods in accordance with § 64 LFBG. For quantitative bacteriological tests, a 10-fold dilution series was made followed by culture-based quantification methods on approved selective media in duplicate. Comparing the results of the final dissection (day 44/45), nearly all samples of animals receiving the own-made complete diet were Campylobacter positive in the caecal content, whereas only seven of fifteen samples were positive in the CON group. With regard to the CFU in the caecal content, the counts of Campylobacter were significantly lower for animals fed the commercial diet (2.47 ± 3.06 vs. 7.36 ± 0.66 log10 CFU/g). When only the positive animals were evaluated, significant differences were also found between the CON group and the total of the other groups (5.30 ± 2.08 vs. 7.54 ± 1.70 log10 CFU/g). Although significant differences were seen in the results, no final recommendation can be given how to create a diet to reduce an infection with Campylobacter.
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Infecciones por Campylobacter/veterinaria , Campylobacter/aislamiento & purificación , Pollos/microbiología , Proteínas en la Dieta/farmacología , Heces/microbiología , Contenido Digestivo/microbiología , Alimentación Animal/análisis , Animales , Campylobacter/clasificación , Campylobacter/efectos de los fármacos , Portador Sano , Dieta/veterinaria , Enfermedades de las Aves de Corral/microbiologíaRESUMEN
Infected laying hens regularly excrete large amounts of Campylobacter jejuni with their feces, which represent a reservoir of infection within the flock and for animals in the region. However, the knowledge about survival times of C. jejuni in these feces is still scarce. Therefore, orienting laboratory experiments were carried out under controlled conditions to estimate the survival times of C. jejuni both in artificially and naturally contaminated laying hen feces. In 6 different laying hen flocks (3 Campylobacter-free and 3 Campylobacter-positive flocks), fresh excreta were randomly collected and pooled in 20-g samples per flock. In the laboratory, each of the 3 pooled samples from the Campylobacter-free barns were homogenized and mixed with 10 mL of a freshly prepared C. jejuni suspension (3 × 10(8) cfu/mL). The other 3 samples were homogenized only. The 6 samples were stored at 20 ± 1°C and 40 to 60% RH in 2 different incubators. Specimens of 2 g were taken from all 6 samples 1 h after storage and daily at the same time during the next 10 consecutive days and investigated on culturable C. jejuni. The survival times of culturable C. jejuni ranged from 72 to 96 h in artificially inoculated feces and varied from 120 to 144 h in naturally colonized flocks. The flaA typing by RFLP confirmed that the isolates from the artificially contaminated feces were identical with the added strain. A total of 5 different flaA types were identified from the naturally contaminated feces, and survival of these isolates was dependent on flaA type. The demonstrated survival times indicate that contaminated fresh feces are an important reservoir of C. jejuni, representing a permanent source of infection over at least 6 d after excretion. It shows the considerable potential of fresh feces in transmitting the agent within and between flocks during that period. This 6-d span should be considered when poultry manure is applied to land as organic fertilizer.
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Infecciones por Campylobacter/veterinaria , Campylobacter jejuni/crecimiento & desarrollo , Pollos , Enfermedades de las Aves de Corral/transmisión , Animales , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana/veterinaria , Infecciones por Campylobacter/transmisión , Campylobacter jejuni/clasificación , Campylobacter jejuni/genética , Campylobacter jejuni/aislamiento & purificación , Heces/microbiología , Femenino , Flagelina/genética , Proteínas de la Membrana/genética , Reacción en Cadena de la Polimerasa/veterinaria , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN/veterinaria , Factores de TiempoRESUMEN
OBJECTIVE: Hydrocephalus is the most common brain disorder in children and is more common in low- and middle-income countries. Research output on hydrocephalus remains sparse and of lower quality in low- and middle-income countries compared with high-income countries. Most studies addressing hydrocephalus epidemiology are retrospective registry studies entailing their inherent limitations and biases. This study aimed to investigate child-related, parental, and socioeconomic risk factors of congenital hydrocephalus (CH) in a lower-middle-income country. METHODS: An investigator-administered questionnaire was used to query parents of patients with CH and controls who visited the authors' institution from 2017 until 2021. Patients with secondary hydrocephalus and children older than 2 years of age at diagnosis were excluded. Uni- and multivariable logistic regression was performed to identify the factors affecting CH development. RESULTS: Seven hundred forty-one respondents (312 cases and 429 controls) were included in this study. The authors showed that maternal diseases during pregnancy (OR 3.12, 95% CI 1.96-5.03), a lack of periconceptional folic acid intake (OR 1.92, 95% CI 1.32-2.81), being a housewife (OR 2.66, 95% CI 1.51-4.87), paternal illiteracy (OR 1.65, 95% CI 1.02-2.69), parental consanguinity (OR 3.67, 95% CI 2.40-5.69), a history of other CNS conditions in the family (OR 2.93, 95% CI 1.24-7.34), conceiving a child via assisted fertilization techniques (OR 3.93, 95% CI 1.57-10.52), and the presence of other congenital anomalies (OR 2.57, 95% CI 1.38-4.87) were associated with an independent higher odds of a child having CH. Conversely, maternal hypertension (OR 0.22, 95% CI 0.09-0.48), older maternal age at delivery (OR 0.93, 95% CI 0.89-0.97), and having more abortions (OR 0.80, 95% CI 0.67-0.95) were negatively correlated with CH. CONCLUSIONS: Multiple parental, socioeconomic, and child-related factors were associated with higher odds for developing CH. These results can be utilized to guide parental counseling and management, and direct social education and prevention programs.
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Países en Desarrollo , Hidrocefalia , Embarazo , Femenino , Humanos , Preescolar , Niño , Estudios de Casos y Controles , Estudios Retrospectivos , Egipto , Factores de Riesgo , Hidrocefalia/etiologíaRESUMEN
Background: Zinc is an anti-inflammatory and antioxidant micronutrient found in food. Due to its well-established role in immunity, it is currently being used in some clinical trials against coronavirus disease-2019 (COVID-19). This study aimed to assess the association between the mean serum zinc level in COVID-19 Egyptian patients and its relationship with disease severity. This cross-sectional study was conducted on sixty patients with confirmed COVID-19 infection. These patients were divided into two groups according to clinical outcome, group 1 which included 30 intensive care unit (ICU) patients and group 2 which included 30 patients who were admitted to the ward. Mean serum levels of zinc were compared between the two groups. Results: There was a statistically significant difference noted among study groups regarding the serum zinc level (p < 0.039), where lower mean serum zinc levels were noted in ICU patients compared to ward patients (70.6 ± 5.7 vs 73.8 ± 6.1). Conclusion: Low serum zinc level is associated with the severe outcome of COVID-19 infection.
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Nonalcoholic fatty liver disease (NAFLD) is a spectrum of hepatic diseases linked to metabolic and cardiovascular disorders that impair quality of life and increase morbidity and mortality. There has been significant interest in replacing conventional diagnostic tools such as liver biopsy with non-invasive biomarkers for the diagnosis of NAFLD. Thymosin Beta 4 (Tß4) is a G-actin sequestering peptide involved in many critical biological processes. This study aimed to evaluate the role of Tß4 in the diagnosis of NAFLD, and its relation to metabolic syndrome. Eighty patients were enrolled in this study, divided into two equal groups of NAFLD cases (n=40) and a control group (n=40). The two groups were subjected to history taking, physical examination, measurement of waist circumference and body mass index (BMI). Laboratory workup included serum Tß4, insulin resistance (HOMA-IR), fibrosis-4 score (FIB-4), fatty liver index (FLI) and NAFLD fibrosis score (NFL) were calculated for both groups. Serum Tß4 was significantly lower in NAFLD patients (P < 0.001) and there was a significant positive correlation between serum Tß4 and HDL (P = 0.034). On the other hand, there was a significant negative correlation between serum Tß4 and waist circumference (P < 0.001), total cholesterol level (P < 0.001), insulin level (P < 0.001), HOMA-IR (P < 0.001), serum triglycerides (P= 0.025) and FLI (P = 0.004). Serum Tß4 at a cut-off value of ≤900 ng/ml had 100 % sensitivity, 100 % specificity, 100% positive predictive value and 100% negative predictive value for the prediction of NAFLD. In conclusion, serum Tß4 could be used as a biomarker for the diagnosis of NAFLD.
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Resistencia a la Insulina , Síndrome Metabólico , Enfermedad del Hígado Graso no Alcohólico , Timosina , Biomarcadores , Egipto , Fibrosis , Humanos , Síndrome Metabólico/diagnóstico , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Calidad de VidaRESUMEN
BACKGROUND: The researchers are trying to evaluate the measurement of: Intact parathyroid hormone (iPTH) and serum total calcium (sCa) levels for predicting hypocalcemia after total thyroidectomy (TT). METHODS: The sample of this single center prospective study consists of (100) patients, where (77) females and (23) males with an age range between (28) and (65) (the mean level is, 48.17 ± 6.54). These selected patients underwent total thyroidectomy (TT) in the general surgery department, Benha university hospital from the period of June 2019 to February 2020. Levels of sCa and iPTH were measured aat several times preoperatively, 10 min, 48 h, 3, 6, 9 months, and 1 year after being after gone TT. RESULTS: Among the entire study sample, 23 patients (23%) developed transient hypoparathyroidism and hypocalcemia (Ë8.5 mg/dl), none of them developed permanent hypoparathyroidism and hypocalcemia. The cut-off point of PTH has been 10 min after TT was at 23 pg/mL as it was the best compromise between sensitivity and specificity for predicting hypocalcaemia. It has been found that Patients who have a PTH greater than 23 pg/mL can be discharged safely after 24 h. Patients who have PTH of less than 23 pg/mL were observed for an additional 24 h, and the study found that timely treatment initiation is recommended. A PTH Ë 10 pg/mL measured at 48 h after surgery had a sensitivity, specificity as well as an accuracy of 100%, for predicting hypocalcemia after TT. The accuracy of a single PTH concentration at 48 h was useful for predicting hypocalcemia [Area under receiver-operator characteristic curve (AUC) 1; confidence interval (CI), 95%, 0.85-0.94]. CONCLUSION: Patients with iPTH Ë 10 pg/mL, and sCa levels Ë 7.4 mg/dL are at higher risk of developing hypoparathyroidism and hypocalcemia after TT.
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Progressive pseudo-rheumatoid dysplasia is an autosomal recessive skeletal dysplasia. Spine radiographs show platyspondyly. The clinical presentations are similar to juvenile idiopathic arthritis, but not the laboratory findings. We report 2 cases of progressive pseudo-rheumatoid dysplasia in the same family. A 26 years old male was admitted in the department of Rheumatology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with the complain of inflammatory joint pain, joint swelling, range-of-motion limitation, and joint deformities in the hands, wrists, ankles, knees and hips for 20 years. He was treated as juvenile idiopathic arthritis with different anti-inflammatory medications having progressing by flares and remissions. Erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, anti ccp antibody and HLAB27 levels were normal. Synovial fluid of the knees showed mechanical properties. Plain radiographs of the hands and knees showed evidence of joint destruction. Radiograph of the pelvis notes bilateral hip dysplasia. Platyspondyly was found in spinal radiograph. The diagnosis of juvenile idiopathic arthritis was reconsidered. His 22 years old younger brother had similar manifestations without laboratory evidence of inflammation; radiographs disclosed dysplasia of the hips and metacarpophalangeal epiphyses. Manifestation of spinal stiffness, thoracic kyphosis, and motion-range limitation at the hips; radiographs showed normal sacroiliac joints and bilateral hip dysplasia. So, a diagnosis of progressive pseudo-rheumatoid dysplasia with polyarticular involvement was done.
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Artritis Juvenil , Artropatías , Adulto , Bangladesh , Humanos , Masculino , Radiografía , Rango del Movimiento Articular , Adulto JovenRESUMEN
Benign cardiac tumors are rare and fibroma is second to rhabdomyoma in frequency in pediatric cardiac tumors. We report a case of a 14-year-old male patient, who presented with shortness of breath for 2 years. Echocardiogram and cardiac magnetic resonance imaging indicated a large mass located in the left ventricular lateral wall. The patient underwent surgical excision of the tumor, and histopathological examination confirmed the diagnosis of a cardiac fibroma. The patient had a good postoperative recovery and was discharged on sixth postoperative day.
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Fibroma/diagnóstico , Neoplasias Cardíacas/diagnóstico , Ventrículos Cardíacos , Adolescente , Ecocardiografía , Fibroma/diagnóstico por imagen , Fibroma/patología , Fibroma/cirugía , Neoplasias Cardíacas/diagnóstico por imagen , Neoplasias Cardíacas/patología , Neoplasias Cardíacas/cirugía , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/cirugía , Humanos , Imagen por Resonancia Magnética , Radiografía TorácicaRESUMEN
BACKGROUND: Electrocautery has been shown to be associated with excessive serous drainage which may lead to many complications in patients with breast cancer needing dissection of the axillary lymph nodes. The Harmonic Focus could outperform electrocautery in dissection of axillary lymph nodes, resulting in shortening of the operative times and minimize postoperative complications. This study aims to compare the mean axillary drain production and the axillary numbness frequency in axillary lymph node dissection (ANLD) during Modified Radical Mastectomy (MRM) and breast conservative surgery (BCS) between the use of harmonics scalpel and electrocautery. METHODS: This study includes 40 patients presented with early breast cancer (T1 and T2) underwent BCS or MRM in general surgery department, Faculty of Medicine, Benha University Hospital during the period from January 2017 to September 2019. The patients randomly assigned into 2 groups; group A: subjected to ANLD using Harmonic Focus tool and group B: subjected to ANLD using electrocautery. Operative time, total drainage volume, blood loss, duration of the drain and frequency of axillary numbness were recorded. RESULTS: This study shows that using Harmonic in axillary dissection considerably reduced operating time, total drainage volume, blood loss, days of hospital stays and reduced axillary numbness level in comparison to conventional electrocautery. CONCLUSION: Compared to the normal electrocautery, the harmonic focus dissection has major advantages in lowering postoperative drainage, blood loss intra-operative and lower incidence of axillary numbness in breast cancer axillary dissection, without affecting operating time.
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We report details of an experimental platform implemented at the National Ignition Facility to obtain in situ powder diffraction data from solids dynamically compressed to extreme pressures. Thin samples are sandwiched between tamper layers and ramp compressed using a gradual increase in the drive-laser irradiance. Pressure history in the sample is determined using high-precision velocimetry measurements. Up to two independently timed pulses of x rays are produced at or near the time of peak pressure by laser illumination of thin metal foils. The quasi-monochromatic x-ray pulses have a mean wavelength selectable between 0.6 Å and 1.9 Å depending on the foil material. The diffracted signal is recorded on image plates with a typical 2θ x-ray scattering angle uncertainty of about 0.2° and resolution of about 1°. Analytic expressions are reported for systematic corrections to 2θ due to finite pinhole size and sample offset. A new variant of a nonlinear background subtraction algorithm is described, which has been used to observe diffraction lines at signal-to-background ratios as low as a few percent. Variations in system response over the detector area are compensated in order to obtain accurate line intensities; this system response calculation includes a new analytic approximation for image-plate sensitivity as a function of photon energy and incident angle. This experimental platform has been used up to 2 TPa (20 Mbar) to determine the crystal structure, measure the density, and evaluate the strain-induced texturing of a variety of compressed samples spanning periods 2-7 on the periodic table.
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Purpose: Laparoscopic techniques to treat pelvic organ prolapse are gaining popularity around the globe due to their low recurrence rates and better functional results compared to perineal techniques. However, the optimum surgical procedures are not yet determined. In the current research, we suggest a novel surgical approach, laparoscopic vaginal suspension with suture rectopexy, to treat multiorgan pelvic prolapse. Methods: This prospective cohort trial was conducted from March 2018 to March 2022 and comprised 35 females with multiorgan pelvic organ prolapse with obstructed defecation symptoms. A residual rectal prolapse was still present despite the manual reduction of uterine prolapse. Patients' conditions before and after the operation were monitored regarding the obstructed defecation score, sexual function, need for laxatives, anorectal manometry pressures, anorectal sensations, and recurrence. The mean follow-up duration was one year. Results: Modified Longo score for obstructed defecation significantly decreased at six and twelve months after surgery. Additionally, a significant reduction was reported in the number of patients who needed laxatives at six and twelve months after surgery. Anorectal manometry pre- and post-surgery showed a significant elevation in the mean squeeze pressure and a decline in all rectal sensations. All parameters of the female sexual function scoring system increased postoperatively. No recurrence was reported during follow-up. Conclusion: For multiorgan pelvic prolapse, laparoscopic vaginal suspension combined with suture rectopexy has excellent functional outcomes, minimal morbidity, and low cost. (AU)
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Humanos , Femenino , Adulto , Laparoscopía , Prolapso de Órgano Pélvico/cirugía , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Abstract Introduction Almost 25% of colorectal cancer (CRC) patients have synchronous colorectal liver metastasis (SCLM) coinciding with the disease diagnosis. Liver-first approach for the treatment of SCLM involves neoadjuvant chemotherapy, subsequent liver resection, and then primary tumor resection. This strategy is adopted as the prognosis of the disease depends mainly on the metastases, not the primary tumor. This study aims to evaluate the feasibility of the liver-first approach and clinical prognosis in managing SCLM. Materials and Methods This retrospective study included 25 patients with SCLM from July 2015 to July 2020. All patients were subjected to a liver-first approach with an "intention-to-treat" approach. Follow-up was planned for at least 3 years. Data were collected from the hospital records and included survival rates and univariate analyses of the prognostic factors, such as gender, age, and number of chemotherapy cycles to evaluate their effect on the survival probability. Results Nineteen patients completed the treatment paradigm. Long-term outcomes reported a median overall survival (OS) of 32 months. One-year and 3-year survival probabilities were 89.5% and 42.1%, respectively. The median disease-free survival was 13 months. The number of metastatic lesions, unilobar versus bilobar disease, and the frequency of administered chemotherapy cycles significantly affected survival (p < 0.05). Seven patients (36.84%) remained disease free (no recurrence) while 2 patients (10.53%) survived with recurrence. The overall mortality included 10 deaths (52.63%) due to recurrence. Conclusion Synchronous colorectal liver metastasis treated with the liver-first approach achieved a notable overall advantage. However, the recurrence rate remained relatively high.
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BACKGROUND: Ventriculoperitoneal (VP) shunting is the most commonly performed procedure in the treatment of hydrocephalus. VP shunt migration can occur at different sites. The aim of the study was to present different sites of abnormal distal shunt location, pathophysiology, and the management in each situation. METHODS: Between 2014 and 2017, all patients with hydrocephalus in the Department of Neurosurgery, Cairo University, were gathered prospectively. All pediatric patients below the age of 12 years with shunt migration of the distal end of the VP shunt were identified. RESULTS: Of 1092 patients operated on by the VP shunt between 2014 and 2017, 15 presented with shunt dysfunction because of distal shunt migration (6 anal, 3 scrotal, 1 colon, 1 peroral, 1 upper lumbar extrusion, 1 paraspinal, 1 penile, and 1 umbilical). Especially upper lumbar extrusion and paraspinal shunt location are extremely rare. All the 15 patients were treated successfully with VP shunts and prospectively followed until they presented with complications on different occasions. CONCLUSIONS: Peritoneal complications are among the most common causes of VP failure. We present a rare complication where the shunt migrates outside the peritoneal cavity elsewhere with ambiguous pathogenesis. Special considerations have to be appointed during the shunt revision surgeries of these cases.
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Catéteres/efectos adversos , Migración de Cuerpo Extraño/etiología , Hidrocefalia/cirugía , Complicaciones Posoperatorias/etiología , Derivación Ventriculoperitoneal/efectos adversos , Preescolar , Humanos , Hidrocefalia/diagnóstico por imagen , Lactante , Masculino , Valor Predictivo de las Pruebas , Estudios RetrospectivosRESUMEN
The objective of this work was to develop an image reconstruction algorithm for 2D dosimetry using Al2O3:C and Al2O3:C,Mg optically stimulated luminescence (OSL) films imaged using a laser scanning system. The algorithm takes into account parameters associated with detector properties and the readout system. Pieces of Al2O3:C films (~8 mm × 8 mm × 125 µm) were irradiated and used to simulate dose distributions with extreme dose gradients (zero and non-zero dose regions). The OSLD film pieces were scanned using a custom-built laser-scanning OSL reader and the data obtained were used to develop and demonstrate a dose reconstruction algorithm. The algorithm includes corrections for: (a) galvo hysteresis, (b) photomultiplier tube (PMT) linearity, (c) phosphorescence, (d) 'pixel bleeding' caused by the 35 ms luminescence lifetime of F-centers in Al2O3, (e) geometrical distortion inherent to Galvo scanning system, and (f) position dependence of the light collection efficiency. The algorithm was also applied to 6.0 cm × 6.0 cm × 125 µm or 10.0 cm × 10.0 cm × 125 µm Al2O3:C and Al2O3:C,Mg films exposed to megavoltage x-rays (6 MV) and 12C beams (430 MeV u-1). The results obtained using pieces of irradiated films show the ability of the image reconstruction algorithm to correct for pixel bleeding even in the presence of extremely sharp dose gradients. Corrections for geometric distortion and position dependence of light collection efficiency were shown to minimize characteristic limitations of this system design. We also exemplify the application of the algorithm to more clinically relevant 6 MV x-ray beam and a 12C pencil beam, demonstrating the potential for small field dosimetry. The image reconstruction algorithm described here provides the foundation for laser-scanned OSL applied to 2D dosimetry.
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Procesamiento de Imagen Asistido por Computador/métodos , Magnesio/química , Dosimetría con Luminiscencia Ópticamente Estimulada/métodos , Algoritmos , Óxido de Aluminio/química , Carbono/química , Rayos Láser , Dosimetría con Luminiscencia Ópticamente Estimulada/instrumentaciónRESUMEN
This work evaluates the dosimetric properties of newly developed optically stimulated luminescence (OSL) films, fabricated with either Al2O3:C or Al2O3:C,Mg, using a prototype laser scanning reader, a developed image reconstruction algorithm, and a 6 MV therapeutic photon beam. Packages containing OSL films (Al2O3:C and Al2O3:C,Mg) and a radiochromic film (Gafchromic EBT3) were irradiated using a 6 MV photon beam using different doses, field sizes, with and without wedge filter. Dependence on film orientation of the OSL system was also tested. Diode-array (MapCHECK) and ionization chamber measurements were performed for comparison. The OSLD film doses agreed with the MapCHECK and ionization chamber data within the experimental uncertainties (<2% at 1.5 Gy). The system background and minimum detectable dose (MDD) were <0.5 mGy, and the dose response was approximately linear from the MDD up to a few grays (the linearity correction was <10% up to ~2-4 Gy), with no saturation up to 30 Gy. The dose profiles agreed with those obtained using EBT3 films (analyzed using the triple channel method) in the high dose regions of the images. In the low dose regions, the dose profiles from the OSLD films were more reproducible than those from the EBT3 films. We also demonstrated that the OSL film data are independent on scan orientation and field size over the investigated range. The results demonstrate the potential of OSLD films for 2D dosimetry, particularly for the characterization of small fields, due to their wide dynamic range, linear response, resolution and dosimetric properties. The negligible background and potential simple calibration make these OSLD films suitable for remote audits. The characterization presented here may motivate further commercial development of a 2D dosimetry system based on the OSL from Al2O3:C or Al2O3:C,Mg.
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Algoritmos , Óxido de Aluminio/química , Dosimetría por Película/instrumentación , Mediciones Luminiscentes/instrumentación , Óptica y Fotónica , Calibración , Relación Dosis-Respuesta en la Radiación , Dosimetría por Película/métodosRESUMEN
Recent advances in surgeons' understanding of the anatomic, biomechanical, and radiologic features of the anterolateral ligament (ALL) of the knee have led to an increased interest in reconstruction of this structure as part of the management of knee instability. Even without any technical flaws and proper positioning of the bone tunnels, there is a small subset of patients, approximately 7% of all patients, who experience some residual anterolateral rotational instability after anterior cruciate ligament reconstruction. For this reason, some researchers have turned again toward the anterolateral aspect of the knee and specifically the ALL. In this technical note, the surgical steps for percutaneous reconstruction of ALL of the knee using a polyester tape are described.
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Recent experiments at the Sandia National Laboratory Z facility have called into question models used in calculating opacity, of importance for modeling stellar interiors. An effort is being made to reproduce these results at the National Ignition Facility (NIF). These experiments require a new X-ray opacity spectrometer (OpSpec) spanning 540 eV-2100 eV with a resolving power E/ΔE > 700. The design of the OpSpec is presented. Photometric calculations based on expected opacity data are also presented. First use on NIF is expected in September 2016.
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A new streaked soft x-ray imager has been designed for use on high energy-density (HED) physics experiments at the National Ignition Facility based at the Lawrence Livermore National Laboratory. This streaked imager uses a slit aperture, single shallow angle reflection from a nickel mirror, and soft x-ray filtering to, when coupled to one of the NIF's x-ray streak cameras, record a 4× magnification, one-dimensional image of an x-ray source with a spatial resolution of less than 90 µm. The energy band pass produced depends upon the filter material used; for the first qualification shots, vanadium and silver-on-titanium filters were used to gate on photon energy ranges of approximately 300-510 eV and 200-400 eV, respectively. A two-channel version of the snout is available for x-ray sources up to 1 mm and a single-channel is available for larger sources up to 3 mm. Both the one and two-channel variants have been qualified on quartz wire and HED physics target shots.