[Guidelines for the follow up of patients with bronchopulmonary dysplasia]. / Protocolo de seguimiento de los pacientes con displasia broncopulmonar.

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth, and remains a major problem in pediatric pulmonology units. The decision of discharging from the Neonatal Unit should be based on a thorough assessment of the condition of the patient and compliance with certain requirements, including respiratory and nutritional stability, and caregiver education on disease management. For proper control of the disease, a schedule of visits and complementary tests should be established prior to discharge, and guidelines for prevention of exacerbations and appropriate treatment should be applied. In this paper, the Working Group in Perinatal Respiratory Diseases of the Spanish Society of Pediatric Pulmonology proposes a protocol to serve as a reference for the follow up of patients with BPD among different centers and health care settings. Key factors to consider when planning discharge from the Neonatal Unit and during follow up are reviewed. Recommendations on treatment and prevention of complications are then discussed. The final section of this guide aims to provide a specific schedule for follow-up and diagnostic interventions to be performed in patients with BPD.

Benzyl derivatives of 2,1,3-benzo- and benzothieno[3,2-a]thiadiazine 2,2-dioxides: first phosphodiesterase 7 inhibitors.

The synthesis of a new family of benzyl derivatives of 2,1,3-benzo- and benzothieno[3,2-a]thiadiazine 2,2-dioxides was achieved. The biological data revealed the first heterocyclic family of compounds with PDE 7 inhibitory properties appearing to be a new objective for the treatment of T-cell-dependent disorders. The IC(50) values or percent inhibition values of the compounds against PDE 7 were calculated by testing them against human recombinant PDE 7 expressed in S. cerevisiae. In this expression system the only cyclic nucleotide hydrolyzing activity present in cell extracts corresponded to human PDE 7. Isoenzyme selectivity PDE 7 versus PDE 4 and PDE 3 was also measured. Considering simultaneously inhibition of the three different isoenzymes, monobenzyl derivatives 15 and 23 showed interesting PDE 7 potency (around 10 microM); although not statistically significant, a trend toward selectivity with respect to PDE 3 and PDE 4 was obtained. Benzothiadiazine 16, although less potent at PDE 7 (IC(50) = 25 microM), also showed a trend of selectivity toward PDE 3 and PDE 4. These compounds are considered the best leads for further optimization.

Phosphodiesterase type 4 isozymes expression in human brain examined by in situ hybridization histochemistry and[3H]rolipram binding autoradiography. Comparison with monkey and rat brain.

We have examined the distribution of four different cyclic AMP-specific phosphodiesterase isozyme (PDE4A, PDE4B, PDE4C and PDE4D) mRNAs in the brain of different species by in situ hybridization histochemistry and by autoradiography with [3H]rolipram. We have compared the localization of each isozyme in human brain with that in rat and monkey brain. We have found that the four PDE4 isoforms display a differential expression pattern at both regional and cellular level in the three species. PDE4A, PDE4B and PDE4D are widely distributed in human brain, with the two latter appearing more abundant. In contrast, PDE4C in human brain, presents a more restricted distribution, limited to cortex, some thalamic nuclei and cerebellum. This is at variance with the distribution of PDE4C in rat brain, where it is found exclusively in olfactory bulb. In monkey brain, the highest expression for this isoform is found in the claustrum, and at lower levels in cortical areas and cerebellum. PDE4B presented a broad distribution, being expressed in both neuronal and non neuronal cell populations. In general, the distribution of binding sites visualized with [3H]rolipram correlated well with the expression of each PDE4 isozyme.

Differential distribution of cAMP-specific phosphodiesterase 7A mRNA in rat brain and peripheral organs.

We investigated the regional distribution and cellular localization of mRNA coding for the cAMP-specific phosphodiesterase 7A (PDE7A) in rat brain and several peripheral organs by in situ hybridization histochemistry. The regional expression of two splice variants, PDE7A1 and PDE7A2, was examined by RT-PCR using RNA extracted from several brain regions. PDE7A mRNA was found to be widely distributed in rat brain in both neuronal and nonneuronal cell populations. The highest levels of hybridization were observed in the olfactory bulb, olfactory tubercle, hippocampus, cerebellum, medial habenula nucleus, pineal gland, area postrema, and choroid plexus. Positive hybridization signals were also detected in other areas, such as raphe nuclei, temporal and entorhinal cortex, pontine nuclei, and some cranial nerve motor nuclei. Both mRNA splice forms were differentially distributed in several areas of the brain with the striatum expressing only PDE7A1 and the olfactory bulb and spinal cord expressing PDE7A2 exclusively. In peripheral organs the highest levels of PDE7A hybridization were seen in kidney medulla, although testis, liver, adrenal glands, thymus, and spleen also presented high hybridization signal. These results are consistent with PDE7A being involved in the regulation of cAMP signaling in many brain functions. The consistent colocalization with PDE4 mRNAs suggests that PDE7A could have an effect on memory, depression, and emesis. The results offer clear anatomical and functional systems in which to investigate future specific PDE7 inhibitors.

Phosphodiesterases 4D and 7A splice variants in the response of HUVEC cells to TNF-alpha(1).

The mRNA accumulation of phosphodiesterases PDE4D and PDE7A was studied by RNA blot analysis in human umbilical vein endothelial cells (HUVEC) incubated with TNFalpha for different periods. A contrasting behaviour was observed in the mRNA accumulation of the two genes. Further analysis by RT-PCR of the PDE4D and PDE7A splice variants gave different accumulation patterns which may indicate that differential splicing has a role in the regulation of these enzymes. Three previously undescribed PDE4D isoforms, with different accumulation patterns, were also detected. They code for truncated PDE4D isoforms, which could participate in the regulation of PDE4D activity.