The effects of hypoxia-ischemia on neutral amino acid transporters in the developing rat brain

The neutral amino acid transporters SNAT1-3 and ASCT1 play critical roles in the recycling of glutamine, and subsequently glutamate, via the glutamine-glutamate cycle. Hypoxia-ischemia was induced in rat pups using the Rice-Vannucci model. Brains were harvested at 1 h, 24 h and 7 days after ischemia. The expression of NAATs was evaluated using immunoblotting, real-time PCR, and immunohistochemistry. Results were compared with age-matched controls and shams. SNAT1 mRNA decreased at 1 h after injury in both hemispheres when compared with the control animals and correlated with a decrease in protein expression at 24 h in the hippocampus and cortex. SNAT1 protein expression increased globally at 7 days after injury and specifically in the hippocampus. Finally, SNAT2 and 3 demonstrated subtle changes in various brain regions after injury. These data suggest that neutral amino acid transporters remain largely intact after hypoxia-ischemia.     

Avidin-biotin system: a small library of cysteine biotinylated derivatives designed for the [99mTc(N)(PNP)]2+ metal fragment

Using the avidin-biotin system as model, we investigate here the effective application of [Tc(N)L(PNP)](+/0) technology (L=N-functionalized cysteine [O(-),S(-)]; PNP=aminodiphosphine) to the preparation of target-specific radiopharmaceuticals. A series of (99m)Tc-nitrido complexes containing functionalized biotin ligands was prepared and their biological profile was determined. To minimize the steric and the electronic influences of the Tc-carrying complex on the biotin-avidin receptor interaction, the following N-functionalized cysteine-biotin derivatives were synthesized: (1) Biot-CysOSH; (2) Biot-Abu-CysOSH; (3) Biot-Abz-CysOSH; (4) Biot-l-(Ac)Lys-CysOSH; (5) Biot-d-(Ac)Lys-CysOSH; (6) Biot-Glu-CysOSH. The asymmetrical nitrido-Tc(V) (99g/99m)Tc(N)(Biot-X-CysOS)(PNP3) (X=spacer) complexes, where PNP3 was N,N-bis-[(dimethoxypropyl)phosphinoethyl] methoxy-ethylamine, were obtained by simultaneous addition of PNP3 and the relevant biotinylated ligand to a solution containing a (99m)Tc-nitrido precursor (yields >95%). In all cases, a mixture of syn- and anti isomers was observed. In vitro challenge experiments with glutathione and cysteine indicated that no transchelation reactions occurred. Assessment of the in vitro binding to avidin of the complexes revealed that only the complexes containing Biot-Abu-CysOS and Biot-Glu-CysOS ligand maintained a good affinity for the concentrator. Stability studies carried out in human and mouse plasma as well as in rat and mouse liver homogenate evidenced a rapid enzymatic degradation for the (99m)Tc(N)(Biot-Abu-CysOS)(PNP3) complex, whereas the (99m)Tc(N)(Biot-Glu-CysOS)(PNP3) one was stable in all conditions. Tissue biodistribution in normal Balb/C mice of the most stable candidate showed a rapid clearance both from the blood and the other tissues. The activity was eliminated both through the hepatobiliary system and the urinary tract.     

Effectiveness of nurse-delivered cardiovascular risk management in primary care: a randomised trial

Background

A substantial part of cardiovascular disease prevention is delivered in primary care. Special attention should be paid to the assessment of cardiovascular risk factors. According to the Dutch guideline for cardiovascular risk management, the heavy workload of cardiovascular risk management for GPs could be shared with advanced practice nurses.

Aim

To investigate the clinical effectiveness of practice nurses acting as substitutes for GPs in cardiovascular risk management after 1 year of follow-up.

Design of study

Prospective pragmatic randomised trial.

Setting

Primary care in the south of the Netherlands. Six centres (25 GPs, six nurses) participated.

Method

A total of 1626 potentially eligible patients at high risk for cardiovascular disease were randomised to a practice nurse group (n = 808) or a GP group (n = 818) in 2006. In total, 701 patients were included in the trial. The Dutch guideline for cardiovascular risk management was used as the protocol, with standardised techniques for risk assessment. Changes in the following risk factors after 1 year were measured: lipids, systolic blood pressure, and body mass index. In addition, patients in the GP group received a brief questionnaire.

Results

A larger decrease in the mean level of risk factors was observed in the practice nurse group compared with the GP group. After controlling for confounders, only the larger decrease in total cholesterol in the practice nurse group was statistically significant (P = 0.01, two-sided).

Conclusion

Advanced practice nurses are achieving results, equal to or better than GPs for the management of risk factors. The findings of this study support the involvement of practice nurses in cardiovascular risk management in Dutch primary care.     

Chemokine/cytokine cocktail in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible fibrosing lung disease of unknown etiology and with an unfavorable outcome, leading ultimately to death due to respiratory failure. To date, no treatment strategies have been effective in modifying the natural course of IPF and its fatal outcome. The aberrant parenchymal remodeling is characterized by the expansion of fibroblasts/myofibroblasts, which form characteristic subepithelial foci, and by the abnormal deposition of extracellular matrix in the lung parenchyma. Although the pathophysiology underlying this disease has not yet been fully elucidated, animal models of pulmonary fibrosis have provided contributions in dissecting the molecular basis of this disease, focusing on the role of cytokines and chemokines as important pathogenetic mediators of lung fibrosis. Starting with the data obtained from animal models, this article provides a comment on a number of findings that suggest the possible role of the chemokine/cytokine system in the pathogenesis of IPF.     

A novel erythroid anion exchange variant (Gly796Arg) of hereditary stomatocytosis associated with dyserythropoiesis

Background

Stomatocytoses are a group of inherited autosomal dominant hemolytic anemias and include overhydrated hereditary stomatocytosis, dehydrated hereditary stomatocytosis, hereditary cryohydrocytosis and familial pseudohyperkalemia.

Design and Methods

We report a novel variant of hereditary stomatocytosis due to a de novo band 3 mutation (p. G796R-band3 CEINGE) associated with a dyserythropoietic phenotype. Band 3 genomic analysis, measurement at of hematologic parameters and red cell indices and morphological analysis of bone marrow were carried out. We then evaluated the red cell membrane permeability and ion transport systems by functional studies of the patient’s erythrocytes and Xenopus oocytes transfected with mutated band 3. We analyzed the red cell membrane tyrosine phosphorylation profile and the membrane association of the tyrosine kinases Syk and Lyn from the Src-family-kinase group, since the activity of the membrane cation transport pathways is related to cyclic phosphorylation-dephosphorylation events.

Results

The patient showed mild hemolytic anemia with circulating stomatocytes together with signs of dyserythropoiesis. Her red cells displayed increased Na⁺ content with decreased K⁺content and abnormal membrane cation transport activities. Functional characterization of band 3 CEINGE in Xenopus oocytes showed that the mutated band 3 is converted from being an anion exchanger (Cl⁻, HCO₃⁻) to being a cation pathway for Na⁺ and K⁺. Increased tyrosine phosphorylation of some red cell membrane proteins was observed in diseased erythrocytes. Syk and Lyn membrane association was increased in the patient’s red cells compared to in normal controls, indicating perturbation of phospho-signaling pathways involved in cell volume regulation events.

Conclusions

Band 3 CEINGE alters function from that of anion exchange to cation transport, affects the membrane tyrosine phosphorylation profile, in particular of band 3 and stomatin, and its presence during red cell development likely contributes to dyserythropiesis.     

Echovirus-4 Meningitis Outbreak Imported from India

We describe seven cases of meningitis in a group of young Italian travelers coming back from India. Virologic studies identified echovirus-4 as the cause of this cluster of cases, the first imported echovirus outbreak in Italy. Enteroviruses may play an important role in undiagnosed fevers in travelers.