RESUMEN

O objetivo deste estudo foi avaliar os efeitos do tacrolimo e da ciclosporina na produção lacrimal de cães com ceratoconjuntivite seca (CCS) durante 90 dias. Para tanto, foram utilizados colírios de tacrolimo 0,02% (TcL) e ciclosporina 0,1% (CsA) em 14 cães com CCS. Os animais foram distribuídos em dois grupos e avaliados antes do início do tratamento (T0) e aos 15 (T1), 30 (T2), 45 (T3), 60 (T4), 75 (T5) e 90 (T6) dias após o início do tratamento. Na avaliação clínica, observou-se maior redução da secreção ocular, da opacidade e do edema corneano e da vascularização conjuntival. no grupo tacrolimo. No teste de Schirmer, verificou-se produção basal de 6(4,07 e 5,86(2,85mm/min no TcL e CsA, respectivamente, com aumento significativo da produção lacrimal em ambos os grupos, contudo houve aumento significativo da produção lacrimal a partir dos 15 dias de tratamento no grupo TcL (17,88(5,51mm/min), mas apenas a partir dos 45 dias no grupo CsA (11,86(4,74mm/min). Conclui-se que o uso do colírio tacrolimo aumentou em 68,83% a produção lacrimal em 90 dias de tratamento, comparado com a ciclosporina (56,82%), além de diminuir as manifestações clínicas inerentes à CCS, quando comparado à terapia com ciclosporina.(AU)

The objective of this study was to evaluate the effects of tacrolimus and cyclosporine on the lacrimal production of dogs with ketaroconjunctivitis sicca (KCS) for 90 days. Tacrolimus 0.02% (TcL) and 0.1% cyclosporine (CsA) eye drops were used in 14 dogs with KCS. The animals were randomly assigned to two groups and evaluated before treatment (T0) and at 15 (T1), 30 (T2), 45 (T3), 60 (T4), 75 (T5) and 90 (T6) days after initiation of treatment. Clinical evaluation showed significant reduction of ocular secretion, corneal opacity and edema and conjunctival vascularization in the tacrolimus group. Schirmer test showed basal lacrimal production of 6(4.07 and 5.86(2.85mm/min for TcL and CsA, respectively, with significant increase in lacrimal production in both groups. There was a significant increase in lacrimal production after 15 days of treatment in the TcL group (17.88(5.51mm/min), but only after 45 days in the CsA group (11.86(4.74mm/min). Tacrolimus drops increased lacrimal production in 68.83% after 90 days of treatment, compared to cyclosporine (56.82%), and also reduced clinical manifestations related to KCS when compared to cyclosporine.(AU)

Asunto(s)

RESUMEN

O objetivo deste estudo foi avaliar os efeitos do tacrolimo e da ciclosporina na produção lacrimal de cães com ceratoconjuntivite seca (CCS) durante 90 dias. Para tanto, foram utilizados colírios de tacrolimo 0,02% (TcL) e ciclosporina 0,1% (CsA) em 14 cães com CCS. Os animais foram distribuídos em dois grupos e avaliados antes do início do tratamento (T0) e aos 15 (T1), 30 (T2), 45 (T3), 60 (T4), 75 (T5) e 90 (T6) dias após o início do tratamento. Na avaliação clínica, observou-se maior redução da secreção ocular, da opacidade e do edema corneano e da vascularização conjuntival. no grupo tacrolimo. No teste de Schirmer, verificou-se produção basal de 6(4,07 e 5,86(2,85mm/min no TcL e CsA, respectivamente, com aumento significativo da produção lacrimal em ambos os grupos, contudo houve aumento significativo da produção lacrimal a partir dos 15 dias de tratamento no grupo TcL (17,88(5,51mm/min), mas apenas a partir dos 45 dias no grupo CsA (11,86(4,74mm/min). Conclui-se que o uso do colírio tacrolimo aumentou em 68,83% a produção lacrimal em 90 dias de tratamento, comparado com a ciclosporina (56,82%), além de diminuir as manifestações clínicas inerentes à CCS, quando comparado à terapia com ciclosporina.(AU)

The objective of this study was to evaluate the effects of tacrolimus and cyclosporine on the lacrimal production of dogs with ketaroconjunctivitis sicca (KCS) for 90 days. Tacrolimus 0.02% (TcL) and 0.1% cyclosporine (CsA) eye drops were used in 14 dogs with KCS. The animals were randomly assigned to two groups and evaluated before treatment (T0) and at 15 (T1), 30 (T2), 45 (T3), 60 (T4), 75 (T5) and 90 (T6) days after initiation of treatment. Clinical evaluation showed significant reduction of ocular secretion, corneal opacity and edema and conjunctival vascularization in the tacrolimus group. Schirmer test showed basal lacrimal production of 6(4.07 and 5.86(2.85mm/min for TcL and CsA, respectively, with significant increase in lacrimal production in both groups. There was a significant increase in lacrimal production after 15 days of treatment in the TcL group (17.88(5.51mm/min), but only after 45 days in the CsA group (11.86(4.74mm/min). Tacrolimus drops increased lacrimal production in 68.83% after 90 days of treatment, compared to cyclosporine (56.82%), and also reduced clinical manifestations related to KCS when compared to cyclosporine.(AU)

Asunto(s)

RESUMEN

OBJECTIVE: To evaluate the effect of leptin and other selected variables on gestational weight gain (GWG) according to pre-gestational body mass index (BMI). DESIGN: Prospective cohort. SETTING: Public Health Center, Rio de Janeiro, Brazil. SAMPLE: Two hundred and twenty-eight pregnant women. METHODS: Women were followed at the 5-13, 20-26 and 30-36th gestational weeks. The effects of independent variables on GWG in normal weight (BMI 18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9 kg/m(2) ) and obese (BMI ≥ 30.0 kg/m(2) ) women were assessed using longitudinal linear mixed-effects models. MAIN OUTCOME MEASURE: Maternal body weight (kg) throughout pregnancy. RESULTS: Leptin concentrations were associated with GWG in normal weight (ß = 0.048, P < 0.001) and overweight (ß = 0.023, P = 0.048) women, but not in obese ones (ß = 0.011, P = 0.308). Additionally, the number of hours slept per night decreased the effect of leptin on GWG in OW women (ß = -0.013, P = 0.002). The effect of other maternal characteristics on GWG was different depending on the BMI category. CONCLUSIONS: Leptin concentrations were positively associated with GWG in normal weight and overweight women, but not in obese ones. Maternal height was associated with GWG in all BMI categories, but other variables such as sleep duration, QUICKI values, HDL-c, smoking habit and marital status presented differential effects according to BMI. We encourage further studies to investigate the association between leptin and gestational weight gain, taking into account the pre-pregnancy weight and sleep duration, in order to compare and confirm our results. TWEETABLE ABSTRACT: Leptin is associated with weight gain in normal weight and overweight pregnant women, but not in obese ones.

Asunto(s)

RESUMEN

We propose a statistical model to account for the gel-fluid anomalous phase transitions in charged bilayer- or lamellae-forming ionic lipids. The model Hamiltonian comprises effective attractive interactions to describe neutral-lipid membranes as well as the effect of electrostatic repulsions of the discrete ionic charges on the lipid headgroups. The latter can be counterion dissociated (charged) or counterion associated (neutral), while the lipid acyl chains may be in gel (low-temperature or high-lateral-pressure) or fluid (high-temperature or low-lateral-pressure) states. The system is modeled as a lattice gas with two distinct particle types--each one associated, respectively, with the polar-headgroup and the acyl-chain states--which can be mapped onto an Ashkin-Teller model with the inclusion of cubic terms. The model displays a rich thermodynamic behavior in terms of the chemical potential of counterions (related to added salt concentration) and lateral pressure. In particular, we show the existence of semidissociated thermodynamic phases related to the onset of charge order in the system. This type of order stems from spatially ordered counterion association to the lipid headgroups, in which charged and neutral lipids alternate in a checkerboard-like order. Within the mean-field approximation, we predict that the acyl-chain order-disorder transition is discontinuous, with the first-order line ending at a critical point, as in the neutral case. Moreover, the charge order gives rise to continuous transitions, with the associated second-order lines joining the aforementioned first-order line at critical end points. We explore the thermodynamic behavior of some physical quantities, like the specific heat at constant lateral pressure and the degree of ionization, associated with the fraction of charged lipid headgroups.

Asunto(s)

RESUMEN

Aqueous dispersions of phosphatidylglycerol (PG) lipids may present an anomalous chain-melting transition at low ionic strengths, as seen by different experimental techniques such as calorimetry or light scattering. The anomaly disappears at high ionic strengths or for longer acyl-chain lengths. In this article, we use a statistical model for the bilayer that distinguishes both lipid chain and headgroup states in order to compare model and experimental thermotropic and electrical properties. The effective van der Waals interactions among hydrophobic chains compete with the electrostatic repulsions between polar headgroups, which may be ionized (counterion dissociated) or electrically neutral (associated with counterions). Electric degrees of freedom introduce new thermotropic charge-ordered phases in which headgroup charges may be spatially ordered, depending on the electrolyte ionic strength, introducing a new rationale for experimental data on PGs. The thermal phases presented by the model for different chain lengths, at fixed ionic strength, compare well with an experimental phase diagram constructed on the basis of differential scanning calorimetry profiles. In the case of dispersions of DMPG (dimyristoyl phosphatidylglycerol) with added monovalent salt, the model properties reproduce the main features displayed by data from differential scanning calorimetry as well as the characteristic profile for the degree of ionization of the bilayer surface across the anomalous transition region, obtained from the theoretical interpretation of electrokinetic (conductivity and electrophoretic mobility) measurements.

RESUMEN

We theoretically investigate the dependence of the surface charge developed on charged spherical colloids upon several environmental parameters: the ionic strength of the monovalent added electrolyte, acidity (stabilized by a pH buffer solution), and colloid concentration. In the framework of the mean-field Poisson-Boltzmann spherical cell model, we include the charged colloid-microion correlations into the buffer equation, and we allow for the specific binding of ions to the ionizable groups on the colloid surface. Theoretical predictions are compared to the results obtained under the planar-symmetry Gouy-Chapman approximation and analyzed for the experimental conditions of an aqueous dispersion of the phospholipid dimyristoyl phosphatidylglycerol (DMPG). Experimental measurements of the partition ratio of an aqueous soluble cationic spin label on buffered dispersions of polyanionic unilamellar vesicles of DMPG in the presence of added monovalent salt are theoretically interpreted in terms of ion partition due to electrostatic interactions. We show that the specific binding of the probe must be admitted to explain the experimental results.