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This work discusses a jellium scheme, built within the framework of the multicomponent Ornstein-Zernike (OZ) equation, which is capable of describing the collective structure of suspensions of highly charged colloids with added salt, even in the presence of finite-size multivalent microions. This approach uses a suitable approximation to decouple the microion-microion correlations from the macroion-microion profiles, which in combination with the methodology from the dressed ion theory (DIT) gives a full account of the electrostatic effective potential among the colloids. The main advantages of the present contribution reside in its ability to manage the short-range potentials and non-linear correlations among the microions, as well as its realistic characterization of the ionic clouds surrounding each macroion. The structure factors predicted by this jellium scheme are contrasted with previously reported experimental results for microgel suspensions with monovalent salts (2019Phys. Rev. E100032602), thus validating its high accuracy in these situations. The present theoretical analysis is then extended to microgel suspensions with multivalent salts, which reveals the prominent influence of the counterion valence on the makeup of the effective potentials. Although the induced differences may be difficult to identify through the mesoscopic structure, our results suggest that the microgel collapsing transition may be used to enhance these distinct effects, thus giving a feasible experimental probe for these phenomena.
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Recent experimental studies have demonstrated the huge influence that the volume phase transition (VPT) has on the collective structure of highly charged thermo-responsive microgels in aqueous solution with low concentrations of added monovalent salt, thus opening a promising new route for controlling the overall properties of practical colloidal suspensions. We present here an analysis of this structure based on the effective electrostatic potential obtained with the exact methodology of the dressed ion theory (DIT). Starting with a description at the primitive model level, we determine the correlations among the components of our model system (macroions plus monovalent anions and cations) by utilizing the two-density integral equation theory, thus allowing us to consider realistic values for the microgel charges. The resulting microgel structure factors show a good agreement with the reported light scattering measurements, whereas the microscopic pair distributions reveal that in this regime the shrunken states promote an enhanced counterion absorption into the microgels. This packing of counterions inside the microgels induces strongly non-linear correlations among the microions, and in turn provokes a substantial weakening of the microgel-microgel correlations. The ensuing effective interactions are then obtained by contracting the description to the level in which only the macroions are present. We find not only that the magnitude and reach of the corresponding pair potentials are markedly inhibited in the shrunken states, but also that their general form diverges from the conventional screened Coulomb shape. This makes it necessary to rethink the concepts of effective charge and screening length.
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Anthropogenic and natural changes are threatening pond ecological integrity in Patagonia and tools for bioassessment are required. Macrophytes are good candidates to determine the conservation status of ponds; nevertheless, metric selection procedures should be founded on an adequate knowledge of plant ecological responses. We assessed the main environmental constraints driving variation in macrophyte assemblages, and trophic status at 29 ponds located at the continental and insular Patagonia region. We screened 20 potential macrophyte metrics as indicators of pond condition that included origin (native, endemic, exotic), lifeforms (annual/biannual, perennial), functional groups (submersed, emergent, floating-leaved, landforms), and community attributes. A set of 106 taxa were recorded, and richness per site (10 species) was unexpectedly high for a cold temperate area, reinforcing the value of isolated ponds as habitat for macrophytes in the Patagonian landscape. Natives dominated most assemblages; exotics were present at 24 ponds, contributing with high cover (>45%) at 15% of them. Macrophyte assemblages were driven by natural factors over anthropogenic ones, with temperature, rainfall, pH, conductivity and nutrients explaining most variation in patterns. However, pond eutrophication symptoms (high phosphorous concentration and chlorophyll a) were associated with extensive cattle grazing (manure and trampling) and urbanization (runoff). Generalized linear models captured natural variables (temperature, alkalinity) as most powerful explaining richness measures. Models also indicated that both richness of emergent and endemics were negatively affected by total phosphorous increases. Land cover factors: grasses/herbaceous, mallín and trees (%) in 100 m buffer around ponds appeared as additional ecological drivers of macrophyte patterns, particularly of submersed (>50%) and native richness (36%). Natural and anthropogenic gradients were overlapped, making it difficult to generalize our conclusions. Further studies are needed to test the performance of the macrophyte metrics selected here, which are a vital tool for the conservation of the most austral ponds in South America.
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Clorofila A , Lagoas , Animais , Argentina , Benchmarking , Bovinos , Ecossistema , América do SulRESUMO
We introduce a theoretical approach to describe structural correlations among charged permeable spheres at finite particle concentrations. This theory explicitly accounts for correlations among microions and between microions and macroions and allows for the proposal of an effective interaction among macroions that successfully captures structural correlations observed in poly-N-isopropyl acrylamide microgel systems. In our description the bare charge is fixed and independent of the microgel size, the microgel concentration, and the ionic strength, which contrasts with results obtained using linear response approximations, where the bare charge needs to be adapted to properly account for microgel correlations obtained at different conditions.
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BACKGROUND: Chronic pain is a major therapeutic problem in kidney transplant patients owing to nephrotoxicity associated with nonsteroidal antiiflammatory drugs. Benefits in chronic pain treatment with cannabidiol (CBD) have been reported. This study assesses the effect, safety, and possible drug interactions in kidney transplant patients treated with CBD for chronic pain. METHODS: We assessed patients who asked to receive CBD for pain treatment. Doses were increased from 50 to 150 mg twice a day for 3 weeks. Creatinine, blood count, liver function, liver enzymes, and drug levels were determined every 48 hours the first week and then once a week thereafter. RESULTS: We assessed 7 patients with a mean age of 64.5 years (range, 58-75 years). CBD initial dose was 100 mg/d, CBD dose reduction to 50 mg/d has been done on day 4 to patient 1 for persistent nausea. Tacrolimus dose reduction in patient 3 was undertaken on days 4, 7, and 21 owing to persisting elevated levels (even before CBD) and itching, and on day 21 in patient 5. Tacrolimus levels decreased in patient 2 but were normal in the control 1 week later. Patients on cyclosporine were stable. Adverse effects were nausea, dry mouth, dizziness, drowsiness, and intermittent episodes of heat. CBD dose decrease was required in 2 patients. Two patients had total pain improvement, 4 had a partial response in the first 15 days, and in 1 there was no change. CONCLUSIONS: During this follow-up, CBD was well-tolerated, and there were no severe adverse effects. Plasma levels of tacrolimus were variable. Therefore, longer follow-up is required.
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Canabidiol/uso terapêutico , Dor Crônica/tratamento farmacológico , Transplante de Rim/efeitos adversos , Manejo da Dor/métodos , Idoso , Dor Crônica/etiologia , Ciclosporina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tacrolimo/uso terapêutico , Resultado do Tratamento , UruguaiRESUMO
BACKGROUND: The Institute of Nephrology and Urology (INU) has performed 75% of kidney transplantations (KT) in Uruguay during its 35 years of activity, with 90.6% from cadaveric donors. We investigated the risk factors (RF) for delayed graft function (DGF) and patient and graft survival (SV). METHODS: We analyzed retrospectively the characteristics and evolution of 1500 KT performed by INU until December 2014. The incidence of DGF and RF for patient and graft SV were analyzed in 4 eras, according to the year that KT was performed. RESULTS: The number of KT per year has progressively increased until reaching 40 KT per million population in 2006, with a decrease of the living donor KT (LDKT) rate. The age of the donors (D) and recipients (R) as well as the time on dialysis (TOD) have progressively increased over the different eras. Five hundred twenty-five R (35%) presented with DGF. The RF for DGF were the age of the R and the D, the TOD, the DDKT, and the warm ischemia time (WIT). In the DDKT group, the cold ischemia time and "died of stroke" were added factors. The death-censored graft SV at 1, 5, 10, and 15 years were 90%, 76%, 62%, and 49%, respectively. They improved as from era I, the patient SV being 92%, 83%, and 75% at 1, 5, and 10 years, in era I; 98%, 93%, and 86% in era II; 98%, 92%, and 83% in era III; and 95% and 90% at 1 and 5 years in era IV (P < .001). The graft SV over the same periods was 76%, 58%, and 40% in era I; 88%, 68%, and 52% in era II; 93%, 81%, and 70% in era III; and 93% and 85% at 1 and 5 years in era IV (P < .0001). The RF for patient SV were diabetes mellitus, era I, lower albuminemia, older age or TOD, and DGF. For kidney SV, the era, the age of the R, TOD, DGF, and D older than 60 years were RF associated with a worse evolution. In DDKT, the RF for the graft SV were the era, younger age of the R, and DGF. The group with the worst graft SV was the one made up of children and adolescents. CONCLUSIONS: Our results relating to patient and graft SV are acceptable and comparable to those mentioned on large records such as the OPNT/SRTR and the Collaborative Transplant Study. This has been the case, even though we have transplanted increasingly aged patients, with increasingly aged donors, or donors with associated pathology. The risk factors that we found both for DGF and SV have also been pointed out by other authors. The validity of some findings has the limitation of being from a retrospective analysis; hence, they should be corroborated by a prospective study.
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Transplante de Rim/estatística & dados numéricos , Academias e Institutos/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Idoso , Cadáver , Criança , Função Retardada do Enxerto/mortalidade , Feminino , Sobrevivência de Enxerto/fisiologia , Humanos , Incidência , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Nefrologia/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Doadores de Tecidos/estatística & dados numéricos , Urologia/estatística & dados numéricos , Uruguai/epidemiologia , Adulto JovemRESUMO
The first kidney transplantation (KT) in Uruguay was performed in 1969. We report the rates of KT and survival of patients and grafts up to December 2014. The country has a surface of 176,215 km(2) and a population of 3,286,314 inhabitants (18.6 inhabitants per km(2)). Till December 31, 2014, 1,940 KT have been performed in Uruguay (41.8 pmp that year); 90.4% of them were from cadaveric donors (CD). Median age of recipients (R) was 44 ± 14 years; R older than 55 years increased from 0 to 27% during the period. Our pre-emptive KT program started in 2007. Optimal donors (D) decreased from 65.2% to 35.5%, and D older than 45 years old increased from 9% to 37%. Trauma as cause of death decreased from 49% to 32% and stroke as cause of death increased from 25% to 39%. Patient survival rates at 1, 5, and 8 years were 93%, 87%, and 78%, respectively for KT performed between 1980 and 1989; they were 98%, 93%, and 89%, respectively, for KT performed between 1990 and1999; they were 97%, 91%, and 90%, respectively, for KT performed between 2000 and 2010. In December 2013, there were 1098 patients pmp in renal replacement therapy, 758 pmp in dialysis, and 340 pmp (30.9%) with a functioning graft. Our national KT program is mainly based (90.6%) on cadaveric donation. Epidemiological changes in the characteristics of R and D followed the changes in aging that occurred in the general population and the dialysis population. The survival rates from patients and kidneys are similar to those reported by the European and the American registries.
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Falência Renal Crônica/terapia , Transplante de Rim/estatística & dados numéricos , Desenvolvimento de Programas , Obtenção de Tecidos e Órgãos/organização & administração , Adulto , Feminino , Humanos , Falência Renal Crônica/epidemiologia , Transplante de Rim/efeitos adversos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Terapia de Substituição Renal/estatística & dados numéricos , Taxa de Sobrevida , Doadores de Tecidos/estatística & dados numéricos , Uruguai/epidemiologiaRESUMO
Kidney transplantation is the best treatment for end-stage chronic renal disease. In Uruguay, the prevalence of patients on dialysis is 757 patients per millon inhabitants, plus 316 alive with a functioning renal graft. We install a preemptive renal transplantation program. Twenty-five patients received grafts without dialysis from 2004 to 2013, 5 receiving their 2nd transplantation and 17 from cadaveric donors, with 7.4 ± 7.7 months in the waiting list. At 24 months, patients' survival rate was 100% and the grafts' 97%, with a serum creatinine of 1.4 ± 0.6 mg%. The developed programs of dialysis and renal health care contributed install our preemptive kidney transplantation. Kidney transplantation should be proposed to selected patients with chronic renal failure as primary therapy of substitution of renal function.
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Falência Renal Crônica/cirurgia , Transplante de Rim , Adolescente , Adulto , Criança , Feminino , Sobrevivência de Enxerto , Humanos , Falência Renal Crônica/mortalidade , Falência Renal Crônica/terapia , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Diálise Renal , Taxa de Sobrevida , Resultado do Tratamento , Uruguai , Listas de Espera , Adulto JovemRESUMO
BACKGROUND: According to our experience, survival of cadaveric renal graft in 5 years increased from 63% as of the introduction of cyclosporine to 73% after azathioprine was substituted with mycophenolate mofetil (MMF) in 1997. Until 2003, the innovator mycophenolate mofetil (IMMF) (Cellcept; Roche) was used. In 2003, Laboratorios Clausen introduced in Uruguay a generic MMF (GMMF) (Suprimun/Micoflavin/Myclausen; Laboratorios Clausen) with previous bioequivalence studies. Since then, every health care provider administers one of these types of MMF available on the market to its renal transplant (RT) patients. METHODS: We compared the evolution of 2 groups of patients and their grafts, those treated with GMMF or with IMMF. This was a descriptive, retrospective, nonrandomized, comparative study that involved all transplant patients in a center from January 2005 to June 2010 from 2 different health care providers which administered GMMF or IMMF uninterruptedly. Patients were older than 18 years, underwent their first RT and received triple immunosuppressive regime with calcineurin inhibitor (CNI), corticoids, and MMF, and completed ≥6 months of post-RT evolution. RESULTS: The GMMF group included 29 patients and the IMMF group 23. Patients from both groups had no significant differences (NS) regarding age, sex, diabetes, hepatitis C virus (HCV), recipient hypertension, donor type (living or cadaveric, sex, age, cause of death), or mismatch degree. There were no material differences regarding antibody induction, CNI type, day of diuresis, or function recovery percentage. Statistically different results were reported for time in dialysis (6.1 ± 0.7 y in IMMF vs 3.8 ± 0.5 y in GMMF) and cadaveric donor cold ischemia time (989 ± 205 min vs 851 ± 219 min, respectively). For IMMF and GMMF, respectively, clinical acute rejection was 40.9% and 31% and creatinine over 3, 6, 12, 24, 36, and 48 months, respectively, was (mg%): 1.65 ± 0.12, 1.66 ± 0.15, 1.43 ± 0.10, 1.44 ± 0.12, 1.49 ± 0.18, and 1.41 ± 0.17 and 1.50 ± 0.08, 1.41 ± 0.07, 1.63 ± 0.26, 1.31 ± 0.08, 1.26 ± 0.09, and 1.21 ± 0.10, with 22/28, 22/28, 22/28, 22/26, 19/20, 17/11, and 15/9 patients under follow-up (NS). Patient survival over 3, 6, 12, and 18 months, respectively, was 94%, 94%, 94%, and 94% and 96%, 96%, 96%, and 96%, and graft survival was 94%, 89%, 89%, and 89% and 96%, 93%, 93%, and 93% for IMMF and GMMF, respectively (NS). Dosing adjustment frequency and substitution with mycophenolate sodium was similar for both groups. CONCLUSIONS: With the results of this preliminary study we can not reach any final conclusion regarding assistance practice. From both groups, which involved similar baseline variables except for time in dialysis and cold ischemia (both greater in IMMF), we could gather a similar graft and patient evolution. New prospective, randomized, double-blind studies involving an adequate number of patients will help to determine the efficacy of GMMF in renal transplantation.
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Medicamentos Genéricos/uso terapêutico , Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Transplante de Rim , Ácido Micofenólico/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/uso terapêutico , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Uruguai , Adulto JovemRESUMO
The suggestion of an anatomical and functional relationship between the basal ganglia and cerebellum is recent. Traditionally, these structures were considered as neuronal circuits working separately to organize and control goal-directed movements and cognitive functions. However, several studies in rodents and primates have described an anatomical interaction between cortico-basal and cortico-cerebellar networks. Most importantly, functional changes have been observed in one of these circuits when altering the other one. In this context, we aimed to accomplish an extensive description of cerebellar activation patterns using cFOS expression (cFOS-IR) after acute and chronic manipulation of dopaminergic activity. In the acute study, substantia nigra pars compacta (SNc) activity was stimulated or suppressed by intra cerebral administration of picrotoxin or lidocaine, respectively. In addition, we analyzed cerebellar activity after the induction of a parkinsonism model, the tremulous jaw movements. In this model, tremulous jaw movements were induced in male rats by IP chronic administration of the dopamine antagonist haloperidol (1.5mg/kg). Acute stimulation of SNc by picrotoxin increased cFOS-IR in the vermis and cerebellar hemispheres. However, lidocaine did not produce an effect. After 14days of haloperidol treatment, the vermis and cerebellar hemispheres showed an opposite regulation of cFOS expression. Chronic dopaminergic antagonism lessened cFOS expression in the vermis but up-regulated such expression in the cerebellar hemisphere. Overall, the present data indicate a very close functional relationship between the basal ganglia and the cerebellum and they may allow a better understanding of disorders in which there are dopamine alterations.