Temperature Dependence of Steady-State and Presteady-State Kinetics of a Type IIb Na+/Pi Cotransporter

The temperature dependence of the transport kinetics of flounder Na+-coupled inorganic phosphate (Pi) cotransporters (NaPi-IIb) expressed in Xenopus oocytes was investigated using radiotracer and electrophysiological assays. 32Pi uptake was strongly temperature-dependent and decreased by ∼80% at a temperature change from 25°C to 5°C. The corresponding activation energy (E a) was ∼14 kcalmol−1 for the cotransport mode. The temperature dependence of the cotransport and leak modes was determined from electrogenic responses to 1 mM Pi and phosphonoformic acid (PFA), respectively, under voltage clamp. The magnitude of the Pi- and PFA-induced changes in holding current decreased with temperature. E a at −100 mV for the cotransport and leak modes was ∼16 kcalmol−1 and ∼11 kcalmol−1, respectively, which suggested that the leak is mediated by a carrier, rather than a channel, mechanism. Moreover, E a for cotransport was voltage-independent, suggesting that a major conformational change in the transport cycle is electroneutral. To identify partial reactions that confer temperature dependence, we acquired presteady-state currents at different temperatures with 0 mM Pi over a range of external Na+. The relaxation time constants increased, and the peak time constant shifted toward more positive potentials with decreasing temperature. Likewise, there was a depolarizing shift of the charge distribution, whereas the total available charge and apparent valency predicted from single Boltzmann fits were temperature-independent. These effects were explained by an increased temperature sensitivity of the Na+-debinding rate compared with the other voltage-dependent rate constant

A Narrative Review on Oral and Periodontal Bacteria Microbiota Photobiomodulation, through Visible and Near-Infrared Light: From the Origins to Modern Therapies

Photobiomodulation (PBM) consists of a photon energy transfer to the cell, employing non-ionizing light sources belonging to the visible and infrared spectrum. PBM acts on some intrinsic properties of molecules, energizing them through specific light wavelengths. During the evolution of life, semiconducting minerals were energized by sun radiation. The molecules that followed became photoacceptors and were expressed into the first proto-cells and prokaryote membranes. Afterward, the components of the mitochondria electron transport chain influenced the eukaryotic cell physiology. Therefore, although many organisms have not utilized light as an energy source, many of the molecules involved in their physiology have retained their primordial photoacceptive properties. Thus, in this review, we discuss how PBM can affect the oral microbiota through photo-energization and the non-thermal effect of light on photoacceptors (i.e., cytochromes, flavins, and iron-proteins). Sometimes, the interaction of photons with pigments of an endogenous nature is followed by thermal or photodynamic-like effects. However, the preliminary data do not allow determining reliable therapies but stress the need for further knowledge on light-bacteria interactions and microbiota management in the health and illness of patients through PBM

Localization of the cyclic ADP-ribose-dependent calcium signaling pathway in bovine rod outer segments.

PURPOSE Calcium ions play a pivotal role in phototransduction. In this study, the presence and functional role of the adenosine diphosphoribosyl (ADPR)-cyclase-cyclic ADP-ribose (cADPR) system in bovine retinal rod outer segments (ROS) was investigated. METHODS A Ca(2+) release from osmotically intact ROS discs elicited by cADPR was studied in the presence of the Ca(2+) tracer fluo-3. Endogenous cyclic guanosine diphosphate ribose (cGDPR) formation in discs was investigated by spectrophotometric detection of its synthesis from nicotinamide guanine dinucleotide (NGD(+)). ADPR-cyclase was also investigated at a structural level on mildly denaturing SDS-PAGE by production of cyclic inosine diphosphate ribose from nicotinamide hypoxantine dinucleotide (NHD(+)). Western immunoblot analysis with a specific antibody was conducted to verify the presence of ryanodine-sensitive Ca(2+) channels (RyRs) in ROS discs. RESULTS cADPR-dependent Ca(2+) release was a linear function of extravesicular free Ca(2+) concentration, between 200 and 900 nM Ca(2+). When free Ca(2+) was 203 +/- 10 nM the mean Ca(2+) release was 23 +/- 3 pmol/mL per milligram protein. The average rate of cGDPR production was 13 +/- 2 nmol cGDPR/min per milligram protein, by a putative enzyme with an apparent molecular mass of 53 +/- 1 kDa. ROS ADPR-cyclase was localized in the membranous fraction. No nicotinamide adenine dinucleotide glycohydrolase (NADase) activity was detected. The presence of RyR channels in pure disc preparations was confirmed by confocal laser scanning microscopy. CONCLUSIONS A cADPR metabolism may be present in retinal ROS discs, which may be Ca(2+) stores operated by cADPR. A model is proposed for the physiological role of cADPR-mediated Ca(2+) release in bovine ROS

Quality indicators for measuring the level of patients' involvement in the pharmaceutical care process

Patient-centred counseling is an integral part of the pharmaceutical care process. Quality in- dicators can be valuable tools to measure the level of patients’ involvement in their personal healthcare. The aim of the study was to validate two quality indicators for community pharmacy care focusing on patient involvement. As part of the EDQM Pharmaceutical Care Quality Indicators Project (Council of Europe), at least 10 patients per indicator were recruited in each community pharmacy in Serbia and Po- land. Pharmacists targeted patients aged 18-65 years starting chronic treatment (Indicator 1) and elderly patients with polymorbidity receiving at least five chronic treatment medicines (Indicator 2). Based on patients’ answers to a questionnaire, patient-pharmacist consultations took place. For Indicator 2, patients were also offered a medication review. In total, 66% of Serbian patients and 29% Polish patients, for In- dicator 1, were engaged in pharmacist-patient consultations; 96% of Serbian and 84% of Polish elderly patients subsequently participated in medication reviews. Community pharmacists can increase patients’ involvement in their own pharmaceutical care, and there is a need for such services. This study defines a pragmatic approach to encourage/support the implementation of the pharmaceutical care philosophy and working methods in European community pharmacies

Discrete Changes in Glucose Metabolism Define Aging

Aging is a physiological process in which multifactorial processes determine a progressive decline. Several alterations contribute to the aging process, including telomere shortening, oxidative stress, deregulated autophagy and epigenetic modifications. In some cases, these alterations are so linked with the aging process that it is possible predict the age of a person on the basis of the modification of one specific pathway, as proposed by Horwath and his aging clock based on DNA methylation. Because the energy metabolism changes are involved in the aging process, in this work, we propose a new aging clock based on the modifications of glucose catabolism. The biochemical analyses were performed on mononuclear cells isolated from peripheral blood, obtained from a healthy population with an age between 5 and 106 years. In particular, we have evaluated the oxidative phosphorylation function and efficiency, the ATP/AMP ratio, the lactate dehydrogenase activity and the malondialdehyde content. Further, based on these biochemical markers, we developed a machine learning-based mathematical model able to predict the age of an individual with a mean absolute error of approximately 9.7 years. This mathematical model represents a new non-invasive tool to evaluate and define the age of individuals and could be used to evaluate the effects of drugs or other treatments on the early aging or the rejuvenation