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INTRODUCTION: After living kidney donation, a decrease of kidney function (described as estimated glomerular filtration rate [eGFR]) is observed in majority of donors. However, the loss is more significant in some patients without an explicable reason. The aim of this study was to identify quantitative parameters in computed tomography (CT) of the abdomen that would predict greater eGFR reduction after kidney removal. MATERIAL AND METHODS: One hundred and ten preoperative multiphase CT examinations of the abdomen of kidney donors were analyzed for the following renal parameters: cortex, parenchyma and pyramids volume, scarring thickness (low grade: <1 cm, high grade: >1 cm), cortical gaps, vascularisation, and cortex-to-aorta enhancement index (CAEI). The radiologic and biometric (eg, donor weight) parameters were correlated with eGFR (CKD-EPI formula) change between baseline and at discharge. RESULTS: Donor weight was correlated with a loss of eGFR (P < .001). Kidney volumetric parameters including renal cortex and parenchyma volume, as well as renal artery cross-section area were associated with donor weight (r = 0.50 P < .001 and r = 0.39 P < .001). CAEI was correlated with a loss of eGFR (P = .003) and was related to the donor's sex in favor of men. Forty-one (37%) donors had an additional renal artery, which did not influence kidney function. No influence of cortical gaps or scarring on eGFR was observed. CONCLUSIONS: CAEI may be a helpful tool in predicting greater short-term kidney function decrease after living kidney donation. Male sex is the strongest risk factor of greater eGFR loss after kidney donation.
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Selección de Donante/métodos , Riñón/diagnóstico por imagen , Donadores Vivos , Cuidados Preoperatorios/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Femenino , Tasa de Filtración Glomerular , Humanos , Riñón/fisiopatología , Trasplante de Riñón/métodos , Masculino , Persona de Mediana Edad , Nefrectomía/efectos adversos , Nefrectomía/métodos , Valor Predictivo de las Pruebas , Periodo Preoperatorio , Arteria Renal/diagnóstico por imagen , Arteria Renal/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Recolección de Tejidos y Órganos/efectos adversos , Recolección de Tejidos y Órganos/métodos , Resultado del TratamientoRESUMEN
BACKGROUND: Renal transplant candidates present immune dysregulation caused by chronic uremia, and deceased kidney donors present immune activation induced by brain death. Pretransplant donor and recipient immune-related gene expression were examined in the search for novel predictive biomarkers crosslinking recipient and donor pretransplant immune status with transplant outcome. MATERIALS AND METHODS: This study included 33 low-risk consecutive renal transplant recipients and matched deceased donors. The expression of 29 genes linked to tissue injury, T-cell activation, cell migration, and apoptosis were assessed in postreperfusion kidney biopsies, as well as 14 genes in pretransplant peripheral blood of the kidney recipients. Gene expression was analyzed with real-time polymerase chain reaction on custom-designed low-density arrays. RESULTS: Donor MMP9 expression was related to delayed graft function occurrence (P = .036) and short term kidney allograft function (14th day rs = -0.44, P = .012; 1st month rs = -0.46, P = .013). Donor TGFB1 expression was associated with short- and long-term graft function (14th day rs = -0.47, P = .007; 3rd month rs = -0.63, P = .001; 6th month rs = -0.52, P = .010; 12th month rs = -0.45, P = .028; 24th month rs = -0.64, P = .003). Donor TGFB1 expression was not related to donor age (rs = 0.32, P = .081), which was also an independent factor influencing the outcome. Recipient gene expression was not related to graft function but determined the acute rejection risk. Recipient IFNG and, to a lesser extent, IL18 expression were protective against acute rejection (area under the curve [AUC] 0.84, P < .001, and AUC 0.79, P < .001, respectively). CONCLUSION: Kidney transplant outcome depends on the interplay between donor-related immune factors, which mostly affect allograft function and recipient immune milieu, influencing an alloreactive response.
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Aloinjertos/inmunología , Funcionamiento Retardado del Injerto/genética , Rechazo de Injerto/genética , Supervivencia de Injerto/genética , Trasplante de Riñón , Adolescente , Adulto , Anciano , Aloinjertos/metabolismo , Área Bajo la Curva , Biomarcadores/metabolismo , Funcionamiento Retardado del Injerto/inmunología , Femenino , Perfilación de la Expresión Génica , Rechazo de Injerto/inmunología , Supervivencia de Injerto/inmunología , Humanos , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-18/inmunología , Interleucina-18/metabolismo , Riñón/inmunología , Riñón/metabolismo , Masculino , Metaloproteinasa 9 de la Matriz/inmunología , Metaloproteinasa 9 de la Matriz/metabolismo , Persona de Mediana Edad , Factores de Tiempo , Donantes de Tejidos , Factor de Crecimiento Transformador beta1/inmunología , Factor de Crecimiento Transformador beta1/metabolismo , Trasplante Homólogo/efectos adversos , Adulto JovenRESUMEN
Complement activation is considered one of the mediators of renal ischemia-reperfusion injury. Elevated levels of C5b-9, C3a, and C5a are detected in sera of deceased kidney donors. The goal of the study was to characterize the functional activity of complement pathways in donor sera and to assess their influence on transplant outcome. MATERIALS AND METHODS: Sixty-four deceased kidney donors (age 45 ± 16 years; 28 female, 36 male) and 27 healthy controls (age 42 ± 12 years; 14 female, 13 male) were enrolled in the study. The results of transplantation for the respective 122 kidney recipients were included in the analysis. The functional activities of classical (CP), lectin (LP), and alternative (AP) pathways were measured using Wielisa-kit (reference normal level = 100%). In most cases, decreased functional activity reflects the activation status of the pathway. RESULTS: The median (interquartile range) functional activities of the pathways in donor sera were CP 118 (89-150)%, LP 80 (20-127)%, and AP 74 (50-89)%, and did not differ from the control values CP 110 (102-115)%, LP 81 (26-106)%, AP 76 (61-88)%. The frequency of pathway activation observed in controls was CP 0%, LP 11%, and AP 0%. Deceased donors did not differ in activation of classical (11%) and lectin (13%) pathways, but presented a higher rate of alternative pathway activation (19%, P = .03). No significant influence of any pathway functional activity or its activation was proved to influence the transplant outcome. CONCLUSION: Complement activation via alternative pathway was observed in diseased donor sera. No predictive potential of donor complement functional activity on the transplant outcome could be proved.
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Aloinjertos/metabolismo , Complemento C3a/fisiología , Complemento C5a/fisiología , Complejo de Ataque a Membrana del Sistema Complemento/fisiología , Riñón/metabolismo , Donantes de Tejidos , Adulto , Activación de Complemento , Femenino , Humanos , Trasplante de Riñón , Lectinas/sangre , Masculino , Persona de Mediana Edad , Daño por Reperfusión/etiologíaRESUMEN
OBJECTIVE: B cell activating factor (BAFF) has been shown to play a role in B cell survival, maturation, and activation, and has been linked with renal transplant outcome. BAFF signaling has been associated with plasmablast survival, anti-HLA immunization, and loss of graft function. We aimed to analyze the interplay between BAFF, memory B cells, and plasmablasts in relation to allograft function in long-term kidney transplant (KTx) recipients and their anti-HLA sensitization. MATERIALS AND METHODS: This study included 70 long-term KTx recipients on standard immunosuppression 15 ± 6 years post transplantation (44 stable, 26 chronic allograft dysfunction, CAD) and 25 healthy volunteers. CD19+ B cells, memory B cells (CD19+CD27+), and plasmablasts (CD19+CD24-CD27++CD38++) were enumerated with flow cytometry. BAFF serum level and anti-HLA antibodies were assessed by Luminex bead arrays. RESULTS: We found no difference in BAFF levels between KTx recipients and controls (median, interquartile range: 1.67, 1.40-1.97 vs 1.78, 1.63-1.93 ng/mL, P = .478) and no correlation between BAFF level and cell counts. Recipients presented lower plasmablast count than controls (22.5, 8-57 vs 79, 48-166 cells/mL, P < .001). There was a positive correlation between estimated glomerular filtration rate and plasmablasts (rs = 0.30, P = .013) in recipients. Cell populations and BAFF were not related to the presence of anti-HLA antibodies. None of the parameters investigated was related to deterioration of allograft function during the 2-year follow-up. CONCLUSION: BAFF serum level is not related to anti-HLA sensitization, circulating memory B cells, plasmablast count, or allograft function. Circulating plasmablasts are associated with current allograft function but are not prognostic for future course.
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Factor Activador de Células B/sangre , Factor Activador de Células B/inmunología , Linfocitos B/inmunología , Supervivencia de Injerto/inmunología , Trasplante de Riñón , Adulto , Aloinjertos/inmunología , Femenino , Citometría de Flujo , Humanos , Masculino , Persona de Mediana Edad , Células Plasmáticas/inmunología , Pronóstico , Trasplante HomólogoRESUMEN
Posttransplant diabetes mellitus (PTDM) adversely affects renal graft and patient survival. Fasting plasma glucose (FPG) alone underestimates diagnosis of glucose metabolism disorders (GMD) detected using the oral glucose tolerance test (OGTT-75). Prediabetes including impaired fasting glucose (IFG): 100 to 125 mg/dL (5.6-6.9 mmol/L) and impaired glucose tolerance (IGT): 140 to 199 mg/dL (7.8-11 mmol/L) 2 hours post 75-g OGTT in the pretransplant period can have a connection with the occurrence of PTDM after renal transplantation (RTx). The aim of our study was to assess the benefit of performing OGTT-75 in dialyzed chronic kidney disease (stage 5) patients on the waiting list for kidney transplantation as a useful tool to prevent PTDM. MATERIALS AND METHODS: Pretransplant glucose testing using OGTT-75 was performed in nondiabetic dialyzed chronic kidney disease patients on the waiting list for renal transplantation in the southwest region of Poland. GMD were diagnosed according to current criteria. Patients with recognized prediabetic stage were recommended a low carbohydrate diet, lifestyle modification, and increased physical activity. In the 12-month posttransplant period we estimated the prevalence of PTDM in the study group based on FPG >126 mg/dL (7 mmol/L) in 2 measurements or random blood glucose >200 mg/dL (11.1 mmol/L). RESULTS: A total of 80 nondiabetic dialysis patients (65 hemodialysis/15 peritoneal dialysis; 47 male/33 female) met initial entry criteria. In pretransplant glucose testing prediabetes was found in 31 out of 80 patients (39%). Among them, 5 patients (6.25%) had combined IGT/IFG, 18 patients (22.5%) had IGT, and 8 patients (10%) had IFG. One year after RTx we recognized PTDM in 14% of all analyzed patients (11/80) and noticed a significant frequency of glucose disorders status change after RTx (P = .002). CONCLUSION: Our findings suggest early detection of prediabetes using the OGTT-75 test in nondiabetic dialysis patients waiting for RTx to prevent occurrence of PTDM.
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Diabetes Mellitus/etiología , Intolerancia a la Glucosa/diagnóstico , Prueba de Tolerancia a la Glucosa/métodos , Trasplante de Riñón/efectos adversos , Estado Prediabético/diagnóstico , Adulto , Glucemia/metabolismo , Diabetes Mellitus/epidemiología , Diagnóstico Precoz , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polonia , Estado Prediabético/etiología , PrevalenciaRESUMEN
BACKGROUND: The role of non-HLA antibodies named antiendothelin A receptor antibodies is potentially significant but not established. The significance of the endothelin A receptor (ETAR) and its expression in renal biopsy has not been defined. We decided to evaluate the presence and relevance of ETARs in renal transplant biopsy for cause. The aim of our study was to evaluate the immunoreactivity of the ETAR and its significance in patients who had a renal transplant biopsy due to deterioration of transplant function (biopsy for cause) with detailed characterization of staining in small and intermediate arteries of renal transplant biopsies. METHODS: Immunohistochemical expression of ETARs was analyzed in 162 renal transplant biopsies. Microscopic evaluation of ETAR expression (polyclonal antibody) was performed on paraffin sections. ETAR expression was analyzed in renal blood vessels (small and intermediate arteries) based on three-step scale. RESULTS: We analyzed 154 patients who had renal allograft biopsy between 6 days and 24 years (median 597 days) after transplantation. Positive staining of ETAR in small and intermediate arteries was noticed in 9 patients. Among these patients, 4 had early biopsies (<3 months after transplantation), all developed acute tubular necrosis, and 1 developed additionally acute humoral rejection. Further, 4 patients had late biopsy (1-8 years after transplantation) and all developed characteristics of antibody mediated rejection. Lastly, 1 patient had no characteristic changes in the biopsy 4 months after transplantation. Graft loss 1 year after biopsy was higher in patients who were ETAR-positive but statistical significance was not achieved. CONCLUSIONS: The expression of endothelin receptors in renal blood vessels (small and intermediate arteries) seems to be important in diagnosis of damage during acute tubular necrosis and antibody-mediated rejection.
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Rechazo de Injerto/inmunología , Trasplante de Riñón/efectos adversos , Riñón/metabolismo , Receptor de Endotelina A/biosíntesis , Adulto , Femenino , Humanos , Riñón/inmunología , Riñón/patología , Masculino , Persona de Mediana Edad , Receptor de Endotelina A/inmunología , Trasplante HomólogoRESUMEN
The occurrence of anti-angiotensin II type 1 receptor (AT1R) antibodies is thought to be a risk factor for transplant injury, but the relationship of AT1R to graft loss in renal transplantation has not been assessed. The aim of our study was to evaluate the expression of AT1R and its relationship with graft loss in patients who had a renal transplant biopsy for cause. METHODS: AT1R immunoreactivity was analyzed in 170 renal transplant biopsies. Immunohistochemical evaluation of AT1R expression was performed on 4 µm-thick paraffin sections mounted on silanized slides. AT1R expression was analyzed in 5 compartments: 1. glomeruli, 2. renal blood vessels (small and intermediate arteries), 3. peritubular capillaries, 4. tubular epithelium, and 5. interstitium based on a 3-step scale. RESULTS: Initially we checked 170 consecutive samples of biopsies for the immunoreactivity of the AT1R. The study finally included 118 renal transplant patients in 1-year observation after the biopsy. The renal allograft biopsy was performed between 6 days and 24 years after transplantation and the diagnosis was based on Banff criteria. We observed positive immunostaining of AT1R in tubular epithelium in 26.3% (42/118) of patients. A total of 7 patients had staining assessed as 2 and 35 as 1. One year post-biopsy graft loss in the AT1R (+) patients was 35.7 % (15/42) compared to 14.5% (11/76) in the AT1R (-) group (P = .008). CONCLUSIONS: The expression of AT1R in tubular epithelium of the biopsy for cause was associated with significantly higher graft loss. The relevance of AT1R should be considered for better transplant immunological risk assessment.
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Trasplante de Riñón , Riñón/metabolismo , Receptor de Angiotensina Tipo 1/biosíntesis , Adulto , Biopsia , Femenino , Rechazo de Injerto/inmunología , Rechazo de Injerto/metabolismo , Humanos , Riñón/inmunología , Riñón/patología , Trasplante de Riñón/efectos adversos , Masculino , Persona de Mediana Edad , Receptor de Angiotensina Tipo 1/inmunología , Factores de Riesgo , Trasplante HomólogoRESUMEN
INTRODUCTION: The prevalence of hypertension in renal graft recipients is high. It was postulated that central arteriovenous anastomosis may significantly reduce blood pressure. This preliminary study evaluates the impact of functioning arteriovenous fistula (AVF) on blood pressure control and renal allograft function. MATERIALS AND METHODS: One hundred sixty-two previously hemodialyzed kidney transplant recipients (108 males, 54 females, aged 52.7 ± 13.2 years, mean 6.9 ± 5.1 years after transplantation), who had scheduled visits in the first two weeks of March 2015, were included in the study. The recipients were divided into two groups depending on AVF function (65 AVF+ and 97 AVF-). RESULTS: Functioning AVF was more prevalent in males than females (47.2 % vs 25.9 %, P = .009). Both groups presented similar allograft function despite the fact that interval from transplantation to examination day in the AVF+ group was significantly shorter than in the AVF- group (5.2 ± 5.3 vs 8.1± 4.5 years; P < .001). The mean systolic blood pressure (135.0 ± 17.0 vs 138.7 ± 14.1 mm Hg, P = .13) was similar in both study groups, but diastolic blood pressure in the AVF+ group was lower than in the AVF- group (80.0 ± 7.0 vs and 83.7 ± 9.2 mm Hg, P = .006). The proportion of patients with diastolic blood pressure >80 mm Hg was significantly higher in patients without functioning AVF (35 % in the AVF- group vs 20 % in the AVF+ group, P= .038). In multivariate analysis, AVF presence was the only factor significantly influencing a diastolic blood pressure with odds ratio 0.43 (95% CI 0.19-0.99, P = .048), which supports AVF as a potentially positive influence on blood pressure control. CONCLUSIONS: The presence of AVF in renal transplant recipients was associated with a slight decrease in diastolic blood pressure without clear effect on renal function.
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Derivación Arteriovenosa Quirúrgica , Hipertensión/etiología , Hipertensión/prevención & control , Trasplante de Riñón , Adulto , Anciano , Presión Sanguínea , Femenino , Humanos , Hipertensión/cirugía , Trasplante de Riñón/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Receptores de Trasplantes , Trasplante HomólogoRESUMEN
INTRODUCTION: Acute central nervous system (CNS) damage in a patient who has received organ transplant is an extremely difficult and complex clinical issue that spans a wide spectrum of differential diagnoses with ischemia, post-transplant lymphoproliferative disorders (PTLDs), infections, lymphomas, and progressive multifocal leukoencephalopathy (PML). PTLDs are a clinically and histopathologically heterogeneous group of diseases that most often occur in heavily immunocompromised populations after solid organ transplantation (SOT), probably related to the infection or reactivation of Epstein-Barr virus (EBV) infection, whereas PML is an infectious disease caused by the John Cunningham virus (JCV). CASE DESCRIPTION: A 56-year-old female, 20 years after renal transplantation from a deceased donor, was admitted to the hospital as an emergency due to sensory aphasia and memory disorders. Computed tomography (CT) examination revealed a diffuse expansive process in the temporo-parieto-occipital and left frontal area. Magnetic resonance imaging (MRI) results suggested changes associated with PML; however, JCV was not found in the cerebrospinal fluid. The disorders progressed quickly, both clinically and radiologically-the patient developed central facial palsy, paresis of limbs, and positive Babinski sign on the left. A second radiological examination (CT) also suggested PML. Due to the rapid deterioration of the patient's general condition, further diagnostic examinations (magnetic resonance with contrast and brain stereotactic biopsy) could not be performed. After almost 2 months of the commencement of the diagnostic process, the patient died. Autopsy revealed that the cause of death was acute CNS damage in the course of monomorphic PTLD (CNS-PTLD). CONCLUSION: Rapid deterioration of mental status can be the first symptom of CNS-PTLD, a dangerous and life-threatening condition in immunocompromised patients after solid organ transplantation.
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Encefalopatías/etiología , Huésped Inmunocomprometido , Trasplante de Riñón/efectos adversos , Trastornos Linfoproliferativos/etiología , Autopsia , Encefalopatías/patología , Diagnóstico Diferencial , Resultado Fatal , Femenino , Humanos , Trastornos Linfoproliferativos/patología , Imagen por Resonancia Magnética , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/patologíaRESUMEN
Previously transplanted highly sensitized patients experience problems with subsequent transplantation. It is also difficult to provide optimal hemodynamic conditions during successive kidney transplantation in heart transplant recipients. PATIENT AND METHODS: We present a case of a 56-year old patient with end-stage renal failure after heart transplantation performed 21 years ago and hemodialyzed using arteriovenous fistula. The patient had 69% panel-reactive antibodies, had been on the active waiting list since 2013, and presented 335 positive crossmatches with deceased donors. He also positively crossmatched with a potential living donor. Detailed examination of anti-HLA antibodies revealed the absence of IgG donor-specific antibodies and negative crossmatch with dithiothreitol-treated serum. The transplantation from his wife was performed with positive crossmatch after 4 plasma exchanges and thymoglobulin induction. Because sympathetic and parasympathetic denervation of the transplanted heart and the presence of arteriovenous fistula induced volume overload of the right heart, we used central venous pressure (CVP) and the PiCCO2 for postsurgical assessment of cardiac output. RESULTS: Monitoring, like CVP and other static exponents of preload obtained by PICCO (extravascular lung water, global end-diastolic volume index) as well as the dynamic parameters obtained by PiCCO2 (pulse pressure variation, stroke volume variation), was not sensitive enough to describe recipient volume status. The immediate graft function was observed, and after 11 months satisfactory estimated glomerular filtration rate is noted with the absence of donor-specific antibodies. CONCLUSION: The history of heart transplantation with existing arteriovenous fistula makes clinical tools such as continuous cardiac output monitoring and CVP parameter inadequate for describing the hemodynamic situation. The high level of panel-reactive antibodies and positive crossmatch possibly caused by IgM antibodies do not have to withdraw the recipient from kidney transplantation.
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Trasplante de Corazón , Monitorización Hemodinámica/métodos , Prueba de Histocompatibilidad/métodos , Trasplante de Riñón/métodos , Derivación Arteriovenosa Quirúrgica , Trasplante de Corazón/métodos , Humanos , Masculino , Persona de Mediana EdadRESUMEN
A novel whole-body positron emission tomography (PET) system based on plastic scintillators is developed by the J-PET Collaboration. It consists of plastic scintillator strips arranged axially in the form of a cylinder, allowing the cost-effective construction of the total-body PET system. In order to determine the properties of the scanner prototype and optimize its geometry, advanced computer simulations were performed using the GATE (Geant4 application for tomographic emission) software. The spatial resolution, sensitivity, scatter fraction and noise equivalent count rate were estimated according to the National Electrical Manufacturers Association norm, as a function of the length of the tomograph, the number of detection layers, the diameter of the tomographic chamber and for various types of applied readout. For the single-layer geometry with a diameter of 85 cm, a strip length of 100 cm, a cross-section of 4 mm × 20 mm and silicon photomultipliers with an additional layer of wavelength shifter as the readout, the spatial resolution (full width at half maximum) in the centre of the scanner is equal to 3 mm (radial, tangential) and 6 mm (axial). For the analogous double-layer geometry with the same readout, diameter and scintillator length, with a strip cross-section of 7 mm × 20 mm, a noise equivalent count rate peak of 300 kcps was reached at 40 kBq cc-1 activity concentration, the scatter fraction is estimated to be about 35% and the sensitivity at the centre amounts to 14.9 cps kBq-1. Sensitivity profiles were also determined.
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Interpretación de Imagen Asistida por Computador/métodos , Fantasmas de Imagen , Tomografía de Emisión de Positrones/instrumentación , Tomografía de Emisión de Positrones/métodos , Conteo por Cintilación/instrumentación , Programas Informáticos , Tomografía Computarizada por Rayos X/métodos , Humanos , Modelos BiológicosRESUMEN
An issue that is currently undergoing extensive study is the influence of human vaginal microbiota (VMB) on the health status of women and their neonates. Healthy women are mainly colonised with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners; however, other bacteria may be elements of the VMB, particularly in women with bacterial vaginosis. The implementation of culture-independent molecular methods in VMB characterisation, especially next-generation sequencing, have provided new information regarding bacterial diversity in the vagina, revealing a large number of novel, fastidious, and/or uncultivated bacterial species. These molecular studies have contributed new insights regarding the role of bacterial community composition. In this study, we discuss recent findings regarding the reproductive tract microbiome. Not only bacteria but also viruses and fungi constitute important components of the reproductive tract microbiome. We focus on aspects related to the impact of the maternal microbiome on foetal development, as well as the establishment of the neonatal microbiomes, including the placenta microbiome, and the haematogenous source of intrauterine infection. We also discuss whether the role of the vaginal microbiome is currently understood and appreciated.
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Lactobacillus/clasificación , Lactobacillus/genética , Microbiota/genética , Placenta/microbiología , Vagina/microbiología , Biodiversidad , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Recién Nacido , Embarazo , Enfermedades Bacterianas de Transmisión Sexual/microbiología , Vaginosis Bacteriana/microbiologíaRESUMEN
In this paper we estimate the time resolution of the J-PET scanner built from plastic scintillators. We incorporate the method of signal processing using the Tikhonov regularization framework and the kernel density estimation method. We obtain simple, closed-form analytical formulae for time resolution. The proposed method is validated using signals registered by means of the single detection unit of the J-PET tomograph built from a 30 cm long plastic scintillator strip. It is shown that the experimental and theoretical results obtained for the J-PET scanner equipped with vacuum tube photomultipliers are consistent.
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Tomografía de Emisión de Positrones/instrumentación , Conteo por Cintilación/instrumentación , Diseño de Equipo , Humanos , Plásticos , Factores de TiempoRESUMEN
We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the [Formula: see text] decays with angular and energy resolution equal to [Formula: see text] and [Formula: see text], respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.
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OBJECTIVE: Left ventricular hypertrophy (LVH) is a risk factor for premature cardiovascular morbidity and mortality in chronic kidney disease. The aim of the study was to determine echocardiographic evaluation morphology and function of the left ventricle in older renal transplantation patients. MATERIAL AND METHODS: We retrospectively analyzed clinical data of renal transplant recipients who underwent routine echocardiography. We compared the data from 38 patients who were older than 65 years with 49 patients who were a mean age of 47.8 ± 12 years (control group). RESULTS: At the time of cardiac evaluation, most patients were in stage 3 chronic kidney disease. In the older group of patients, the incidence of obesity and diabetes were significantly higher than in the control group. Also in the older patients, the serum level of albumin was lower (P < .001), and brain natriuretic peptide was higher (P = .046). The incidence of coronary heart disease, chronic heart failure, and atrial fibrillation were higher in the older patients (P = .011). LVH was common in older as well as younger patients (97.4% vs. 88.8%, P = .17). Left ventricle mass index ranged from 90.4 g/m(2) to 235.5 g/m(2) among examined kidney transplantation patients. In older patients, left ventricular mass index was 160.7 ± 34.5 g/m(2) compared to 141.8 ± 29.8 g/m(2) in younger patients (P = .008). Reduced ejection fraction was found only in 2 of 38 (5.3%) older patients. Diastolic dysfunction of left ventricle was present in 34 of 38 (89.5%) patients >65 years old and in 24 of 49 (49.9%) younger patients (P < .001). CONCLUSIONS: LVH and left ventricular dysfunction are more pronounced among older patients. Impaired renal function, proteinuria, diabetes, and severity of hypertension are the most important factors predisposing to LVH.
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Hipertrofia Ventricular Izquierda/epidemiología , Trasplante de Riñón/efectos adversos , Complicaciones Posoperatorias/epidemiología , Insuficiencia Renal Crónica/cirugía , Disfunción Ventricular Izquierda/epidemiología , Adulto , Anciano , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/etiología , Ecocardiografía/efectos adversos , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Hipertensión/complicaciones , Hipertrofia Ventricular Izquierda/etiología , Incidencia , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Prevalencia , Insuficiencia Renal Crónica/complicaciones , Estudios Retrospectivos , Factores de Riesgo , Disfunción Ventricular Izquierda/etiologíaRESUMEN
BACKGROUND: The beneficial influence of kidney (KTx) or simultaneous pancreas and kidney transplantation (SPK) on quality of life (QOL) in patients with end-stage kidney disease caused by type 1 diabetes mellitus was confirmed in many studies. The aim of this study was to identify factors that influence QOL of patients in long-term follow-up after SPK or KTx. METHODS: Twenty-seven SPK and 26 KTx patients with good function of transplanted organs at least 1 year after transplantation were enrolled into the analysis. To estimate QOL of the recipients the Kidney Disease and Quality of Life Short Form was applied. RESULTS: Within the whole analyzed group, the necessity of exogenous insulin administration correlated (P < .05) with symptom/problem list (γ = -0.35), effects of kidney disease (-0.38), cognitive function (-0.47), sleep (-0.42), overall health (-0.47), physical functioning (-0.61), role-physical (-0.32), pain (-0.50), general health (-0.32), emotional well-being (-0.31), role-emotional (-0.36), social function (-0.33), energy/fatigue (-0.44), and the SF-12 physical composite (-0.44). History of cardiovascular episode correlated (P < .05) with symptom/problem list (γ = -0.59), effects of kidney disease (-0.46), burden of kidney disease (-0.56), sleep (-0.54), social support (-0.51), physical functioning (-0.55), role-physical (-0.70), pain (-0.60), general health (-0.57), emotional well-being (-0.45), role-emotional (-0.95), social function (-0.58), energy/fatigue (-0.59), SF-12 physical composite (-0.45), and SF-12 mental composite (-0.83). CONCLUSIONS: Exogenous insulin administration and history of cardiovascular episode are the most important factors influencing QOL in patients after SPK or KTx, particularly worsening its physical components.
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Diabetes Mellitus Tipo 1/complicaciones , Cardiomiopatías Diabéticas/complicaciones , Nefropatías Diabéticas/psicología , Fallo Renal Crónico/psicología , Trasplante de Riñón/psicología , Trasplante de Páncreas/psicología , Calidad de Vida , Adulto , Terapia Combinada , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/psicología , Cardiomiopatías Diabéticas/psicología , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/cirugía , Femenino , Humanos , Insulina/uso terapéutico , Fallo Renal Crónico/etiología , Fallo Renal Crónico/cirugía , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Periodo PreoperatorioRESUMEN
BACKGROUND: Kidney transplantation (KTx) markedly reduces mortality in patients with end-stage kidney disease (ESKD) caused by type 1 diabetes mellitus (T1DM). The outstanding issue is whether transplantation should be limited only to KTx, with further insulinotherapy, or combined with pancreas transplantation in patients with ESKD/T1DM. The goal of this study was to compare the results of simultaneous pancreas-kidney transplantation (SPKTx) and deceased donor KTx and to identify factors affecting patient and kidney graft survival in patients with ESKD/T1DM. METHODS: Eighty-seven deceased donor KTx and 66 SPKTx operated on in the Silesia region of Poland between 1998 and 2013 were included in the retrospective analysis. RESULTS: During the mean 6.7 ± 3.6 years of follow-up, fewer cardiovascular episodes were observed in SPKTx recipients than in KTx recipients (1.5% vs 12.6%; P < .05). Five-year patient survival (80.7% in SPKTx vs 77.5% in KTx) and kidney graft survival (66.1% in SPKTx vs 70.4% in KTx) did not differ between study groups. There were no differences in patient survival (log-rank test, P = .99) or kidney graft survival (P = .99) based on Kaplan-Meier curves. Multivariable Cox proportional hazard analysis failed to identify factors explaining patient and kidney graft survival. Five-year pancreas graft survival was 58.9%. SPKTx recipients had significantly higher estimated glomerular filtration rates during the 7-year posttransplant period and less frequently developed proteinuria (6.1% vs 23%; P < .01). CONCLUSIONS: Pancreas transplantation reduced cardiovascular risk and prevented the development of proteinuria but did not improve patient and kidney graft survival in recipients with T1DM in the 7-year follow-up period.
Asunto(s)
Diabetes Mellitus Tipo 1/cirugía , Supervivencia de Injerto , Trasplante de Riñón , Trasplante de Páncreas , Adulto , Enfermedades Cardiovasculares/epidemiología , Femenino , Humanos , Trasplante de Riñón/efectos adversos , Trasplante de Riñón/mortalidad , Masculino , Persona de Mediana Edad , Trasplante de Páncreas/efectos adversos , Trasplante de Páncreas/mortalidad , Polonia , Proteinuria/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
Recent tests of a single module of the Jagiellonian Positron Emission Tomography system (J-PET) consisting of 30 cm long plastic scintillator strips have proven its applicability for the detection of annihilation quanta (0.511 MeV) with a coincidence resolving time (CRT) of 0.266 ns. The achieved resolution is almost by a factor of two better with respect to the current TOF-PET detectors and it can still be improved since, as it is shown in this article, the intrinsic limit of time resolution for the determination of time of the interaction of 0.511 MeV gamma quanta in plastic scintillators is much lower. As the major point of the article, a method allowing to record timestamps of several photons, at two ends of the scintillator strip, by means of matrix of silicon photomultipliers (SiPM) is introduced. As a result of simulations, conducted with the number of SiPM varying from 4 to 42, it is shown that the improvement of timing resolution saturates with the growing number of photomultipliers, and that the [Formula: see text] configuration at two ends allowing to read twenty timestamps, constitutes an optimal solution. The conducted simulations accounted for the emission time distribution, photon transport and absorption inside the scintillator, as well as quantum efficiency and transit time spread of photosensors, and were checked based on the experimental results. Application of the [Formula: see text] matrix of SiPM allows for achieving the coincidence resolving time in positron emission tomography of [Formula: see text]0.170 ns for 15 cm axial field-of-view (AFOV) and [Formula: see text]0.365 ns for 100 cm AFOV. The results open perspectives for construction of a cost-effective TOF-PET scanner with significantly better TOF resolution and larger AFOV with respect to the current TOF-PET modalities.
Asunto(s)
Fotones , Plásticos/efectos de la radiación , Tomografía de Emisión de Positrones/métodos , Conteo por Cintilación/métodos , Conteo por Cintilación/instrumentaciónRESUMEN
In microbiological terms, pharmaceutical products can be divided into two groups: sterile and non-sterile. Non-sterile drugs must satisfy the appropriate microbiological purity criteria which are included in pharmacopoeial monographs. Pharmacopoeial studies are prepared specifically with a view to ensuring that the medicinal product is therapeutically effective and safe for the patient. The analysis comprised the results of microbiological purity tests performed before the products are marketed. Total of 1285 samples of non-sterile drugs manufactured by different pharmaceutical plants in Polish were taken into study. The microbiological quality of drugs was assessed in accordance with the criteria included in the European Pharmacopoeia (EP). An analysis of test results demonstrated that the percentage of non-compliant samples was 1.87%. The groups of drugs, which the most often did not satisfy EPs' requirements, were drugs containing raw materials of natural origin (5.7%). The samples of studied drugs that did not meet the criteria contained in EP, exceed the maximum allowable microbiological count limits and contained microbes whose presence is prohibited. The most common non-compliance was the excessive levels of the maximum acceptable fungal count (n = 12) and the excessive the maximum acceptable aerobic microbial count (n = 10).