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Juvenile psammomatoid ossifying fibroma (JPOF) is a rare tumor that occurs in maxillary sinus or orbit. Complete removal is required due to the aggressive and locally destructive nature. It is hard to distinguish from psammomatoid meningioma in cranial lesion and to remove completely. The authors are presenting a case of 26-year-old male with JPOF on skull base and report this case with review of literature.
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Fibroma Ossificante/diagnóstico por imagem , Neoplasias da Base do Crânio/diagnóstico por imagem , Adulto , Fibroma Ossificante/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Nasais/diagnóstico por imagem , Neoplasias Nasais/patologia , Neoplasias dos Seios Paranasais/diagnóstico por imagem , Neoplasias dos Seios Paranasais/patologia , Neoplasias da Base do Crânio/patologia , Tomografia Computadorizada por Raios XRESUMO
IMPROTANCE: Correction of caudal septal deviation with a batten graft has been popularized recently. However, few reports have documented the surgical outcomes of this technique, especially the use of bony batten grafts in septoplasty. OBJECTIVE: To evaluate the surgical outcomes of bony batten grafting for the management of caudal septal deviation in endonasal septoplasty. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study evaluates the medical records of 141 patients with caudal septal deviation who underwent septoplasty using bony batten grafts from September 1, 2011, through February 29, 2016, at a tertiary referral hospital. Patients were divided into primary and secondary surgery groups. Patients were also divided into the septoplasty plus turbinate surgery and the septoplasty only group. Endoscopic assessment of deviation correction was performed, and postoperative complications were analyzed. MAIN OUTCOMES AND MEASURES: Patient satisfaction and symptom improvement were evaluated via telephone interviews by using the Nasal Obstruction Symptoms Evaluation (NOSE) scores. RESULTS: Of the 141 patients (24 women [17%] and 117 men [83%]; mean [SD] age, 32.8 [12.9] years), 86 (61%) rated their symptoms in the postoperative survey as much improved; 50 (35.5%), improved; 4 (2.8%), no change; and 1 (0.7%), worse. All patients had significantly improved mean (SD) postoperative NOSE scores (28.7 [22.0]; 95% CI, 25.0-32.4) compared with preoperative scores (70.5 [26.7]; 95% CI, 66.0-75.0; P < .001). No significant intergroup differences were observed in surgical outcome between the 116 patients undergoing primary surgery (mean [SD] NOSE score, 28.2 [21.9]) and 25 undergoing secondary surgery (mean [SD] NOSE score, 30.8 [24.3]; P = .34). No significant difference in surgical outcome was found between the 102 patients in the turbinate surgery group (mean [SD] NOSE score, 28.1 [20.8]) and 39 in the septoplasty only group (mean [SD] NOSE score, 30.4 [23.7]; P = .65). On endoscopic examination for surgical outcome, 128 patients (90.8%) had a straight septum and 13 (9.2%) had improved but residual caudal deviation. Postoperative complications included septal hematoma in 4 patients, hyposmia in 2, and chondritis in 1; all patients were treated successfully. Four patients required revision surgery because of incomplete functional correction or a desire for rhinoplasty. CONCLUSIONS AND RELEVANCE: Septoplasty using bony batten grafts is useful for correcting caudal septal deviation with favorable surgical outcomes and an acceptable complication rate. LEVEL OF EVIDENCE: 3.
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Transplante Ósseo/métodos , Septo Nasal/cirurgia , Rinoplastia/métodos , Adulto , Endoscopia , Feminino , Humanos , Masculino , Obstrução Nasal/cirurgia , Deformidades Adquiridas Nasais/cirurgia , Estudos Retrospectivos , Inquéritos e Questionários , Resultado do TratamentoRESUMO
OBJECTIVE: The purpose of this study was to evaluate the effect of late applied negative pressure on postoperative drain output after primary total hip arthroplasty (THA). PATIENTS AND METHODS: 100 patients (100 hips) were treated by closed suction drainage applying negative pressure immediately after THA (group I). The remaining 100 patients (100 hips) were treated by the same drainage system, but the negative pressure was not applied in the first 24 h after THA and then negative pressure was applied (group II). RESULTS: The mean total drain output was different between the two groups (group I: 597 ± 200.1 mL, group II: 403 ± 204.1 mL; p < 0.05). Reported drain output from immediate postoperative to postoperative day one was 369 ± 125.5 ml in group I and 221 ± 141.3 ml in group II (p < 0.05). The change of hemoglobin from immediate postoperative to 24 h after THA was lower in group II (group I: 1.5 ± 0.62 g/dL, group II: 1.1 ± 0.73 g/dL; p = 0.004). The mean unit number of blood transfusions was 1.0 (range, 0.0-5.0) in group I and 0.3 (range, 0.0-2.0) in group II (p < 0.05). There was no difference in Harris hip score between the two groups at postoperative 1 year or last follow-up (p = 0.073). CONCLUSION: The minor change in drain system management can reduce postoperative blood loss after primary THA and the need for transfusion. LEVEL OF EVIDENCE: Level III, Therapeutic study.
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Artroplastia de Quadril/métodos , Necrose da Cabeça do Fêmur/cirurgia , Cuidados Pós-Operatórios/normas , Complicações Pós-Operatórias/cirurgia , Guias de Prática Clínica como Assunto , Adulto , Feminino , Necrose da Cabeça do Fêmur/diagnóstico , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Retrospectivos , Sucção/normasRESUMO
Revision rhinoplasty in Asian patients is associated with problems related to the use of grafts or implant materials. Moreover, the septal cartilage of Asian individuals is generally weak and small, which makes it particularly vulnerable to injury or secondary deformity during primary surgery. Hence, there is an increased demand for major reconstruction of the septal cartilage framework during revision surgery in Asian patients. In revision rhinoplasty of the nose in Asian patients, appropriate management of the graft or implant is vital. The common problems resulting in the need for revision surgery include displacement, malposition, extrusion, recurrent inflammation, and infection of dorsally implanted alloplastic material. A short-nose deformity following silicone rhinoplasty is also a common problem that is difficult to manage. Furthermore, residual or recurrent deviation of the deviated nose, undercorrection of the convex nasal dorsum, and tip graft-related complications are frequently encountered problems that require revision. In revision rhinoplasty for Asian patients, autologous tissues, such as conchal cartilage and costal cartilage, play a pivotal role for use as a new dorsal implant or building block for major septal reconstruction. Therefore, it is imperative for surgeons to familiarize themselves with the appropriate use of autologous tissues, particularly costal cartilage.
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Povo Asiático , Deformidades Adquiridas Nasais/cirurgia , Próteses e Implantes/efeitos adversos , Rinoplastia/efeitos adversos , Rinoplastia/métodos , Cartilagem Costal/transplante , Humanos , Cartilagens Nasais/cirurgia , Deformidades Adquiridas Nasais/etiologia , Falha de Prótese , ReoperaçãoRESUMO
BACKGROUND: Early stage osteonecrosis of the femoral head (ONFH) has many treatment options including core decompression with implantation of a tantalum rod. The purpose of this study was to evaluate clinical and radiological outcomes and potential complications during conversion total hip arthroplasty (THA) in such patients. METHODS: Six male patients (8 hips) underwent THA subsequent to removing a tantalum rod (group I) from April 2010 to November 2011. We retrospectively reviewed the medical records of these patients. We enrolled 12 age- and sex-matched patients (16 hips) during the same period, who had undergone primary THA without a previous operation as the control group (group II). All patients were followed for at least 3 years. We checked the Harris hip score (HHS), operative time, and volume of blood loss. Radiological results, including inclination, anteversion of the acetabular cup, presence of periprosthetic osteolysis, and subsidence of femoral stem were checked at the last follow-up. RESULTS: The mean preoperative HHS values were 56.5 (range, 50 to 62) and 59.1 (range, 42 to 70) in groups I and II, respectively. The HHS improved to 96.0 (range, 93 to 100) and 97.6 (range, 93 to 100), respectively, at the 3-year follow-up (p = 0.172). Mean operation time was 98.8 minutes (range, 70 to 120 minutes) in group I and 77.5 minutes (range, 60 to 115 minutes) in group II (p = 0.006). Total blood loss volumes were 1,193.8 mL (range, 960 to 1,360 mL) and 944.1 mL (range, 640 to 1,280 mL) in groups I and II, respectively (p = 0.004). No significant differences in inclination or anteversion of acetabular cup and no evidence of osteolysis or subsidence of the femoral stem were reported in either group in radiological follow-up results. However, one case of squeaking occurred in group I during the follow-up. CONCLUSIONS: The two groups showed no clinical or radiological differences except extended operative time and increased blood loss. However, the incidence of squeaking (1 of 8 hips) was higher, as compared to the control group or previously reported values.
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Artroplastia de Quadril , Descompressão Cirúrgica , Necrose da Cabeça do Fêmur/cirurgia , Tantálio/uso terapêutico , Adulto , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Artroplastia de Quadril/estatística & dados numéricos , Estudos de Casos e Controles , Descompressão Cirúrgica/efeitos adversos , Descompressão Cirúrgica/métodos , Descompressão Cirúrgica/estatística & dados numéricos , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/cirurgia , Necrose da Cabeça do Fêmur/diagnóstico por imagem , Humanos , Masculino , Complicações Pós-Operatórias , Reoperação , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Ankylosing spondylitis is a chronic inflammatory multisystem disease that primarily affects the axial joints. Pleuropulmonary involvement is an uncommon extra-articular manifestation of ankylosing spondylitis. There is a wide spectrum of pulmonary parenchymal changes in ankylosing spondylitis, beginning in the early stages of the disease and increasing over time. The lesions are usually asymptomatic, and not visible on chest radiographs in early stages. We reported a case of advanced ankylosing spondylitis in a 56-year-old man with progressive pulmonary bullous fibrocystic changes on both upper lobes that were misdiagnosed as tuberculosis in the early stages of the disease.
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BACKGROUND: The development of other primary cancers in patients with lung cancer is unfortunate and uncommon, although the frequency is increasing. The aim of this study was to determine the clinical features and prognosis in patients with multiple primary cancers (MPC) involving lung cancer. METHODS: After a retrospective review of 1644 patients who were newly diagnosed with primary lung cancer between 1998 and August 2012 at a tertiary hospital, 105 patients were included. RESULTS: The median age at the time of lung cancer diagnosis was 67 years, and 68 patients were male. Synchronous primary cancers occurred in 47% of the study population (49/105). Among those with metachronous cancer (56/105), the median interval between the diagnosis of lung cancer and another malignancy was 47.1 months; 21 patients were diagnosed with lung cancer as the first primary tumor. The most frequent type of other malignancy was urogenital (30%), followed by gastrointestinal (30%) and thyroid malignancies (16%). Advanced stage of lung cancer (hazard ratio (HR), 3.2; 95% confidence interval (CI), 1.8-5.7; P < 0.001), supportive care only as treatment for lung cancer (HR, 2.8; 95% CI, 1.3-6.0; P = 0.006), and head and neck cancer as another malignancy (HR, 3.9; 95% CI, 1.4-10.8; P = 0.010) were independent predictors of shorter survival from the time of diagnosis of the second primary cancer. CONCLUSION: Advanced lung cancer stage, symptomatic supportive care only without antitumor therapy for lung cancer, and head and neck cancer as another primary malignancy were poor prognostic factors in patients with MPC involving primary lung cancer.
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Gibberellins affect various plant development processes including germination, cell division and elongation, and flowering. A large number of studies have been carried out to address the molecular mechanisms that mediate gibberellin signalling effects on plant growth. However, such studies have been limited to DELLA protein degradation; the regulatory mechanisms controlling how the stability and function of SLEEPY1 (SLY1), a protein that interacts with target DELLA proteins as components of the Skp, Cullin, F-box (SCF)(SLY1) complex, are modulated at the post-translational level have not been addressed. In the present study, we show that the E3 SUMO (small ubiquitin-related modifier) ligase AtSIZ1 regulates gibberellic acid signalling in Arabidopsis species by sumoylating SLY1. SLY1 was less abundant in siz1-2 mutants than in wild-type plants, but the DELLA protein repressor of ga1-3 (RGA) was more abundant in siz1-2 mutants than in wild-type plants. SLY1 also accumulated to a high level in the SUMO protease mutant esd4. Transgenic sly1-13 mutants over-expressing SLY1 were phenotypically similar to wild-type plants; however, sly1-13 plants over-expressing a mutated mSLY1 protein (K122R, a mutation at the sumoylation site) retained the mutant dwarfing phenotype. Over-expression of SLY1 in sly1-13 mutants resulted in a return of RGA levels to wild-type levels, but RGA accumulated to high levels in mutants over-expressing mSLY1. RGA was clearly detected in Arabidopsis co-expressing AtSIZ1 and mSLY1, but not in plants co-expressing AtSIZ1 and SLY1. In addition, sumoylated SLY1 interacted with RGA and SLY1 sumoylation was significantly increased by GA. Taken together, our results indicate that, in Arabidopsis, AtSIZ1 positively controls GA signalling through SLY1 sumoylation.
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Alquil e Aril Transferases/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Giberelinas/metabolismo , Ligases/metabolismo , Transdução de Sinais/fisiologia , Sumoilação/fisiologia , Alquil e Aril Transferases/genética , Substituição de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Giberelinas/genética , Ligases/genética , Mutação de Sentido Incorreto , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismoRESUMO
OBJECTIVES: The purpose of this study was to evaluate the usefulness of retroauricular hair line incision (RAHI) in partial superficial parotidectomy by comparison with modified Blair incision or facelift incision. METHODS: Medical records of 73 patients with benign parotid tumor who underwent partial superficial parotidectomy were retrospectively reviewed. Size and location of tumors, operative time, occurrence of facial nerve paralysis and Frey's syndrome, and cosmetic outcomes were compared among RAHI, facelift incision (FLI), modified Blair incision (MBI) groups. RESULTS: RAHI group showed better cosmetic results than FLI group or MBI group compared with other type of incisions (P<0.001, P<0.001, respectively). Among the 3 groups, there were no significant differences of operative time and location of tumor (P=0.377), size of tumor (P>0.999), occurrence of temporary or permanent facial nerve paralysis (P=0.745) and Frey's syndrome (P=0.940). CONCLUSION: Partial superficial parotidectomy can be done safely by RAHI in most cases of benign parotid tumor. Compared with MBI or FLI, RAHI has better cosmetic outcome with no increase of operative time or postoperative complications.
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OBJECTIVES: This study evaluated the risk factors for anastomotic leakage (AL) and survival outcomes in patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Patients with HNSCC who underwent surgery carrying potential AL from 2003 through 2009 were included in this study. Univariate and multivariate analyses were performed and patient survival was calculated by the Kaplan-Meier method. RESULTS: Of 232 eligible patients, 25 (10.8%) developed AL. Univariate analyses revealed that primary tumor site, salvage surgery, perineural invasion, radiotherapy, chemotherapy, and blood transfusion were significantly associated with the occurrence of AL (P<0.05). Independent risk factors for AL were salvage surgery and blood transfusion (P<0.01). On univariate analysis, AL was significantly associated with overall (OS) and disease-free survivals (DFS; P<0.05) but not with decreased locoregional control (LRC) rate (P=0.07). The 5-year DFS rate was significantly different between the non-leakage and leakage groups (70.9% vs. 27.7%, P<0.001). Multivariate analysis showed, however, that AL was not an independent variable of LRC, DFS, or OS (P>0.1). CONCLUSION: Patients who received salvage surgery and blood transfusion may require careful surveillance for development of AL, which has a tendency toward decreased survival.
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BACKGROUND: This study evaluated surgical outcomes after endonasal septoplasty using caudal septal batten grafting for caudal septal deviation. METHODS: Fifty-six patients completed questionnaires to assess nasal obstruction by telephone interviews 8-63 months postoperatively (12.2 months on the average). In addition, patients assessed the severity of nasal symptoms (i.e., mouth breathing, mouth dryness, hyposmia, rhinorrhea, epistaxis, trouble sleeping, snoring, and being concerned about nasal problems) preoperatively and postoperatively using a visual analog scale (VAS). These VAS scores were compared with those of patients who underwent endonasal septoplasty using the cutting and suture technique. Complications were analyzed. RESULTS: Thirty-four (60.7%) patients reported their nasal obstruction was much improved, 17 (30.3%) reported their condition was improved, and 5 (8.9%) reported no change postoperatively. Patients reported a decrease in severity of all nasal symptoms (p < 0.05 for each). Their nasal obstruction improvement was not significantly different from that of patients managed by the cutting and suture technique. Complications after surgery included hyposmia in two cases, small septal perforation in one case, chondritis in one case, and septal abscess in one case, and all were managed successfully. No patient required revision septoplasty due to recurrence during the follow-up period. CONCLUSION: Endonasal septoplasty using caudal septal batten grafting for caudal septal deviation resulted in improvement in nasal obstruction and nasal symptoms and was associated with an acceptable complication rate.
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Transplante de Tecido Encefálico/efeitos adversos , Perfuração do Septo Nasal/etiologia , Septo Nasal/cirurgia , Doenças Nasais/cirurgia , Complicações Pós-Operatórias , Adolescente , Adulto , Idoso , Cauda Equina/patologia , Progressão da Doença , Seguimentos , Humanos , Pessoa de Meia-Idade , Obstrução Nasal , Septo Nasal/patologia , Doenças Nasais/diagnóstico , Doenças Nasais/patologia , Doenças Nasais/fisiopatologia , Rinoplastia/métodos , Septo do Cérebro/patologia , Septo do Cérebro/transplante , Técnicas de Sutura , Resultado do TratamentoRESUMO
OBJECTIVE: To assess palatine tonsil size relative to degree of obesity in children with sleep-disordered breathing (SDB). STUDY DESIGN: Case-control study. SETTING: Tertiary care rhinology clinic. SUBJECTS AND METHODS: We compared the subjective and objective tonsil size, including tonsil height (TH), tonsil width (TW), tonsil thickness (TT), tonsil weight (TWt), and tonsil volume (TV), in 26 obese children and 26 age- and gender-matched control children with SDB, and in 29 overweight children and 29 matched controls with SDB. RESULTS: Despite similar subjective tonsil size in obese and control children, the objective tonsil size, including TH, TW, TT, and TWt, was larger in obese than in control children, and the mean TV was significantly greater in obese than in control children with SDB (8.53 +/- 3.30 mL vs 6.90 +/- 2.05 mL; 95% confidence interval [CI] of the difference 0.03-3.25; P = 0.019). In contrast, mean TV (7.38 +/- 3.43 mL vs 7.65 +/- 1.97 mL; 95% CI -1.92 to 1.37; P = 0.320) as well as the other parameters of objective palatine tonsil size, including TH, TW, TT, and TWt, did not differ significantly between overweight children and controls. CONCLUSION: Obese children with SDB had larger palatine tonsils than did normal-weight children with SDB. This finding suggests that larger palatine tonsils may have a greater effect on upper airway obstruction in obese than in normal-weight children with SDB.
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Obesidade/patologia , Sobrepeso/patologia , Tonsila Palatina/patologia , Síndromes da Apneia do Sono/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Tamanho do ÓrgãoRESUMO
OBJECTIVE: The purpose of this study was to evaluate imaging findings in noncalcified ductal carcinoma in situ (DCIS) and to compare histologic findings between noncalcified and calcified DCIS. METHODS: From January 2005 to May 2008, 195 patients with pathologically confirmed DCIS were recruited. Among these, 36 patients (18%) had noncalcified DCIS. We retrospectively reviewed their imaging findings according to the American College of Radiology Breast Imaging Reporting and Data System. We also reviewed pathologic reports for all patients with DCIS to obtain information on the histologic type, nuclear grade, and biological markers. RESULTS: Among the 36 patients with noncalcified DCIS, 21 (58%) were symptomatic. On mammography, 25 patients (69%) showed abnormal findings, and 11 patients showed false-negative findings. On sonography, 29 of 36 patients (81%) showed a mass, whereas the remaining 7 patients (19%) showed nonmass lesions. The sonographic findings for the masses were variable: 25 of 29 masses (86%) were irregular in shape; 14 of 29 (48%) showed indistinct margins; and 9 (31%) were angular or spiculated. The orientation of the mass was not parallel in 6 of 29 cases (21%). Two of 29 masses (7%) showed an echogenic halo at the lesion boundary. Noncalcified DCIS tended to have a nonhigh nuclear grade and was frequently the noncomedo type. In addition, c-erb-B2 was more commonly expressed in calcified DCIS. CONCLUSIONS: Imaging findings for noncalcified DCIS are relatively nonspecific and are frequently similar to those of invasive malignancy. This knowledge may be useful for detecting noncalcified DCIS, planning treatment, and predicting the prognosis.
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Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico , Carcinoma Ductal de Mama/diagnóstico por imagem , Adulto , Idoso , Biomarcadores Tumorais , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/patologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Mamografia , Pessoa de Meia-Idade , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Estudos Retrospectivos , Sensibilidade e Especificidade , Ultrassonografia MamáriaRESUMO
OBJECTIVE: The aim of the study was to compare the accuracy of magnetic resonance imaging (MRI) and mammography for the detection and assessment of the size of ductal carcinoma in situ (DCIS). MATERIALS AND METHODS: The preoperative contrast-enhanced MRI and mammography were analyzed in respect of the detection and assessment of the size of DCIS in 72 patients (age range: 30-67 years, mean age: 47 years). The MRI and mammographic measurements were compared with the histopathologic size with using the Pearson's correlation coefficients and the Mann-Whitney u test. We evaluated whether the breast density, the tumor nuclear grade, the presence of comedo necrosis and microinvasion influenced the MRI and mammographic size estimates by using the chi-square test. RESULTS: Of the 72 DCIS lesions, 68 (94%) were detected by MRI and 62 (86%) were detected by mammography. Overall, the Pearson's correlation of the size between MRI and histopathology was 0.786 versus 0.633 between mammography and histopathology (p < 0.001). MRI underestimated the size by more than 1 cm (including false negative examination) in 12 patients (17%), was accurate in 52 patients (72%) and overestimated the size by more than 1 cm in eight patients (11%) whereas mammography underestimated the size in 25 patients (35%), was accurate in 31 patients (43%) and overestimated the size in 16 patients (22%). The MRI, but not the mammography, showed significant correlation for the assessment of the size of tumor in noncomedo DCIS (p < 0.001 vs p = 0.060). The assessment of tumor size by MRI was affected by the nuclear grade (p = 0.008) and the presence of comedo necrosis (p = 0.029), but not by the breast density (p = 0.747) or microinvasion (p = 0.093). CONCLUSION: MRI was more accurate for the detection and assessment of the size of DCIS than mammography.
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Neoplasias da Mama/diagnóstico , Carcinoma in Situ/diagnóstico , Carcinoma Ductal de Mama/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Distribuição de Qui-Quadrado , Meios de Contraste , Diagnóstico Diferencial , Gadolínio DTPA , Humanos , Mamografia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos RetrospectivosRESUMO
Large amounts of CH4 in the form of solid hydrates are stored on continental margins and in permafrost regions. If these CH4 hydrates could be converted into CO2 hydrates, they would serve double duty as CH4 sources and CO2 storage sites. We explore here the swapping phenomenon occurring in structure I (sI) and structure II (sII) CH4 hydrate deposits through spectroscopic analyses and its potential application to CO2 sequestration at the preliminary phase. The present 85% CH4 recovery rate in sI CH4 hydrate achieved by the direct use of binary N2+CO2 guests is surprising when compared with the rate of 64% for a pure CO2 guest attained in the previous approach. The direct use of a mixture of N2+CO2 eliminates the requirement of a CO2 separation/purification process. In addition, the simultaneously occurring dual mechanism of CO2 sequestration and CH4 recovery is expected to provide the physicochemical background required for developing a promising large-scale approach with economic feasibility. In the case of sII CH4 hydrates, we observe a spontaneous structure transition of sII to sI during the replacement and a cage-specific distribution of guest molecules. A significant change of the lattice dimension caused by structure transformation induces a relative number of small cage sites to reduce, resulting in the considerable increase of CH4 recovery rate. The mutually interactive pattern of targeted guest-cage conjugates possesses important implications for the diverse hydrate-based inclusion phenomena as illustrated in the swapping process between CO2 stream and complex CH4 hydrate structure.
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Dióxido de Carbono/química , Água/química , Cinética , Modelos Moleculares , Conformação Molecular , Nitrogênio/química , Análise Espectral RamanRESUMO
Post-transplant lymphoproliferative disease (PTLD) is a serious, often fatal complication after solid organ transplantation. The incidence of PTLD is greater among heart (2 approximately 13%), lung (12%) and heart/lung (5 approximately 9%) transplant recipients than among liver (2%), renal (1 approximately 3%) and bone marrow (1 approximately 2%) transplants recipients. The difference in the incidence of PTLD may be partly attributed to the higher dose of immunosuppressant therapy used for heart and lung transplantation. The Epstein-Barr virus (EBV) infection status of the donor and recipient before a transplant, and high dose of immunosuppressive drugs are considered major risk factors. Recently, 2 cases of PTLD in a single lung and a heart-lung transplantation recipient were encountered. Both patients presented with multiple pulmonary nodules in the transplanted lung, which developed 6 months and 2 years after the transplantation, respectively. Following a transthoracic lung biopsy for diagnostic confirmation, one patient underwent chemotherapy for PTLD and the other conservative care for an accompanying viral infection. Both patients showed rapid clinical deterioration, without response to treatment, and then rapidly succumbed. Herein, our experiences are reported, with a review of the literature.