Recommendations for the prevention and diagnosis of asthma in children: Evidence from international guidelines adapted for Mexico

BACKGROUND

With the availability of high-quality asthma guidelines worldwide, one possible approach of developing a valid guideline, without re-working the evidence, already analysed by major guidelines, is the ADAPTE approach, as was used for the development of National Guidelines on asthma.

METHODS

The guidelines development group (GDG) covered a broad range of experts from medical specialities, primary care physicians and methodologists. The core group of the GDG searched the literature for asthma guidelines 2005 onward, and analysed the 11 best guidelines with AGREE-II to select three mother guidelines. Key clinical questions were formulated covering each step of the asthma management.

RESULTS

The selected mother guidelines are British Thoracic Society (BTS), GINA and GEMA 2015. Responses to the questions were formulated according to the evidence in the mother guidelines. Recommendations or suggestions were made for asthma treatment in Mexico by the core group, and adjusted during several rounds of a Delphi process, taking into account: 1. Evidence; 2. Safety; 3. Cost; 4. Patient preference - all these set against the background of the local reality. Here the detailed analysis of the evidence present in BTS/GINA/GEMA sections on prevention and diagnosis in paediatric asthma are presented for three age-groups: children with asthma ≤5 years, 6-11 years and ≥12 years.

CONCLUSIONS

For the prevention and diagnosis sections, applying the AGREE-II method is useful to develop a scientifically-sustained document, adjusted to the local reality per country, as is the Mexican Guideline on Asthma.

[Validation of a visual analog scale to measure dyspnea in patients with diffuse interstitial lung disease]

In order to validate a form of measuring dyspnea, a visual analog scale (VAS) was applied to 27 patients with different types of interstitial lung diseases (ILD). The test was done in two days with an interval of one month (dyspnea1 and dyspnea2). Additionally, the forced vital capacity (FVC) was obtained on these occasions (FVC1, FVC2). Nineteen patients with a recent diagnosis of ILD (RD) and eight with a previous diagnosis of ILD (PD) were included. In patients with RD, dyspnea1 correlated with FVC1 (r = -0.66, p < 0.01). A month after the initial treatment with steroids, dyspnea (mean +/- SD) decreased from 38 +/- 25 mm to 17 +/- 19 mm (p < 0.03), while the FVC increased from 1086 +/- 464 mL to 1350 +/- 536 mL (p < 0.05). Likewise, dyspnea2 correlated with FVC2 (r = -0.47, p < 0.05). As expected, patients with PD did not exhibit significant changes in the analysis of dyspnea on the second evaluation. The inter-observer coefficient of variation for the 8 patients with PD was of 5% and 9% for the first and second evaluations respectively, while the intraclass correlation coefficient was 0.92 and 0.91 respectively. The intra-observer coefficient of variation of two different observers was of 15% and 16% respectively, while the intraclass correlation coefficient was 0.69 and 0.62 respectively. These results suggest that the use of a VAS might be useful for the initial evaluation and during the follow-up of patients with ILD.

Sulfation of estrone and 17 beta-estradiol in human liver. Catalysis by thermostable phenol sulfotransferase and by dehydroepiandrosterone sulfotransferase

Sulfation is a major pathway in humans for the biotransformation of estrogens. However, the nature of the enzymes that catalyze the sulfation of estrone (E1) and 17 beta-estradiol (E2) in human liver is unclear. Human liver contains at least three well-characterized cytoplasmic sulfotransferases, the thermostable (TS) and thermolabile (TL) forms of phenol sulfotransferase (PST) and dehydroepiandrosterone sulfotransferase (DHEA ST). Therefore, we determined optimal conditions for the assay of E1 and E2 ST activities in human hepatic cytosol to compare their properties and regulation with those of the three well-characterized human liver ST activities. Thermal inactivation studies showed that human liver E2 ST and TS PST had very similar thermal stabilities. The thermal inactivation profile of E1 ST suggested that this activity might be related to both DHEA ST and TS PST. Inhibition studies performed with 2,6-dichloro-4-nitrophenol (DCNP) also showed similar inhibition profiles for E2 ST and TS PST. Neither thermal inactivation nor DCNP inhibition studies indicated a possible relationship between TL PST activity and E1 or E2 sulfation. Experiments performed with 20 individual human liver samples showed highly significant correlations between activity levels of E2 ST and TS PST (rs = 0.944, p less than 0.0001), E1 ST and DHEA ST (rs = 0.845, p less than 0.0001), and, to a lesser degree, E1 ST and TS PST (rs = 0.608, p less than 0.01). Ion exchange chromatography of a human liver preparation, followed by assay of all five ST activities, confirmed the important roles played by TS PST and DHEA ST in the sulfation of E2 and E1. Similar results were found by study of the elution patterns of ST activities after ion exchange chromatography of human jejunal mucosal preparations. Partially purified TL PST, however, was unable to catalyze the sulfate conjugation of either E1 or E2. All of these results were compatible with the conclusion that, in human liver, TS PST is the enzyme predominantly responsible for the sulfate conjugation of E2, DHEA ST is the major enzyme responsible for the sulfation of E1, and TL PST does not appear to catalyze the sulfation of either E1 or E2.

Human liver arylamine N-sulfotransferase activity. Thermostable phenol sulfotransferase catalyzes the N-sulfation of 2-naphthylamine

Our experiments were performed to determine whether human liver, like that of other mammals, could catalyze the N-sulfation of an arylamine, 2-naphthylamine (2-NA) and, if so, whether this reaction might be catalyzed by one or both of the two known forms of human phenol sulfotransferase (PST). One form of PST is thermostable (TS) and catalyzes the sulfation of "simple" phenols such as p-nitrophenol, while the other form is thermolabile (TL) and catalyzes the sulfate conjugation of phenolic monoamines such as dopamine. When 2-NA that was not contaminated with 2-naphthol was used as substrate, human hepatic cytosol could catalyze the N-sulfation of 2-NA with an apparent Km of 322 microM. However, substrate kinetics of the sulfate donor for the reaction, 3'-phosphoadenosine-5'-phosphosulfate, were biphasic, with estimated apparent Km values of 0.13 and 2.2 microM for high and low affinity activities, respectively. Human liver arylamine N-sulfotransferase (AANST) activity was similar to that of TS but not TL PST with regard to thermal stability, inhibition by 2,6-dichloro-4-nitrophenol (DCNP), and regulation among individuals. For example, average temperatures that produced 50% inactivation of TL PST, TS PST, and AANST activities, measured with both 0.05 and 1.0 mM 2-NA as substrate, were 35.0, 40.5, 40.3 and 40.5 degrees C, respectively. IC50 values for the inhibition by DCNP of TL PST, TS PST, and AANST, measured with 0.05 and 1.0 mM 2-NA as substrate, were 110, 1.8, 1.3, and 4.0 microM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Thiopurine methyltransferase regulation in rat kidney: immunoprecipitation studies

1. Thiopurine methyltransferase (TPMT) catalyses the S-methylation of thiopurine drugs. TPMT activity in the kidneys of male Sprague-Dawley (S-D) rats is approximately twice that present in the kidneys of female S-D rats, and this difference is testosterone-dependent. Renal TPMT activities in these animals also increase dramatically during growth and development. 2. Our studies were conducted to determine whether variations in TMPT activity in the S-D rat kidney were due to differences in the quantity of TPMT protein. Rabbit polyclonal antibodies to partially purified rat kidney TPMT were used to develop an immunoprecipitation assay for immunoreactive TPMT protein. 3. Gender-related differences in renal TPMT activities in S-D rats were due to a lower content of immunoreactive TPMT protein in kidneys of female animals. TPMT enzyme activities and immunoreactive protein levels were also directly correlated in renal preparations from castrated and sham-operated male rats, from testosterone-treated castrated and sham-operated male rats, and from testosterone-treated and control female rats. 4. There was also a significant positive correlation between TPMT enzymic activities and immunoreactive TPMT protein levels in renal tissue from different aged male S-D rats (rs = 0.955, n = 15, P less than 0.001.) 5. These results demonstrate that changes in S-D kidney TPMT activity during growth and development, in the two sexes and in response to testosterone, were due to variations in the quantity of immunoreactive TPMT protein.