EXHALED BREATH TEMPERATURE IN ASTHMATIC CHILDREN.

Asthma is characterized by chronic inflammation of airways. Currently, no traditional method allows an easy daily evaluation of the degree of airway inflammation. Measuring inflammatory biomarkers in the breath is a very attractive approach to monitor asthma inflammation. In recent years, the measurement of exhaled breath temperature (EBT) has been proposed as a method capable of detecting the inflammatory status of the airways. The objective of this study is to strengthen the role of EBT in the diagnosis and monitoring of asthma. The study sample was represented by a group of 40 patients, of both sexes, aged 6-15 years. The elective criteria for submitting patients to EBT determination were abstaining from drugs in the preceding 24 h, fasting for at least 2 h, physical resting for at least 30 minutes, a body temperature between 35-37°C. The temperature in the room of the surveys ranged from 18 to 25°C. The EBT values of asthmatic patients were higher [(median (IQR): 29.77°C (30.67°C to 29.38°C) range 28.46°C min-max 34.78°C] than those of non-asthmatic ones (median (IQR): 28.22°C (29.09°C-27.7°C), range 27.09°C min-max 30.07°C] and this difference was highly significant (p less than 0.001). Furthermore, no significant difference was found between the EBT values of the following groups of patients: those exposed and not exposed to passive smoking, those receiving and not receiving leukotriene drugs, those receiving and not receiving specific immunotherapy, monoallergic patients and poliallergic ones, those sensitized and not sensitized to house dust, perennial allergic patients and seasonal allergic ones. In addition, the evaluation of the correlation of EBT values with body temperature (r=0.119, p=0.464) and ambient temperature (r=-304, p = 0.057) did not show any significant correlation. Finally, no statistically significant correlation was demonstrated between EBT values and FEV1 (r=-0055, p=0.81, Fig. 4). In conclusion, the data of the present study further support the hypothesis that EBT can be considered a good method for monitoring asthma.

RELATION OF BODY MASS INDEX WITH IgE LEVELS, ALLERGIC SENSITIZATION AND LUNG FUNCTION IN ASTHMATIC CHILDREN: OUR EXPERIENCE AND REVISION OF LITERATURE.

In recent decades, there has been an increase in the prevalence of asthma and obesity in pediatric age. In this regard several studies have provided controversial data to demonstrate the link between Body Mass Index (BMI) and asthma, both in adults and in children. In this prospective study we evaluated the relationship between body mass index value, total IgE immunoglobulin E levels, skin prick test (SPT) sensitization and lung function in children affected by asthma. According to the analysis of data on the comparison of normal-weight patients versus overweight/obese patients, there was no significant difference in the values of FEV1 (86%±12 vs 90%±19), FVC (81%±11 vs 88%±18), skin prick tests (22.72% vs 36.66%) and total IgE values (192.22±368.28 vs 503±914.04). We carried out a sub-analysis to study the difference between three groups of patients: normal weight, overweight and obese. Obese patients showed higher total IgE values than normal-weight patients with a statistically significant difference. Conversely, there was no significant difference between the normal weight group and the obese group in the respiratory function tests and the SPT. Moreover, we found a higher value of total IgE in female overweight/obese compared with normal weight, while there was no significant difference in relation to parameters of lung function and SPT. However, the same analysis in the male sample did not show any statistically significant difference. This study confirms the higher incidence of atopy in obese children, especially in female gender, but not a direct relationship with either allergens sensitization or abnormal lung function.

Growth hormone receptors in hypothalamic and extra-hypothalamic tissues.

Central GH receptors (GHR) have been identified in hypothalamic and extra-hypothalamic tissues of rabbit and chicken brains. Plasma membranes of the rabbit brain demonstrated specific saturable high-affinity, low-capacity binding sites for 125I-labelled GH. RNA extracted from hypothalamic and extra-hypothalamic tissues of rabbit and chicken brains contained mRNA that hybridized with a cDNA probe for the rabbit liver GHR. This transcript was of a similar size to the major GHR mRNA moiety in rabbit liver. The expression of these moieties was age related, and higher in adult than in neonatal animals.

Homologous and heterologous regulation of somatostatin-binding sites on chicken adenohypophysial membranes.

Binding of 125I-labelled [Tyr1]-somatostatin (125I-[Tyr1]-SRIF) to pituitary caudal lobe membranes was suppressed in immature chickens 1 and 2 h after i.v. administration of unlabelled SRIF at concentrations of 1-100 micrograms/kg. In-vitro preincubation of chicken pituitary glands for 0.5-4.0 h with 0.1 mumol SRIF/l similarly reduced the binding of 125I-[Tyr1]-SRIF to caudal lobe membrane preparations. After a 4-h incubation in 0.1 mmol SRIF/l, the withdrawal of SRIF from the incubation media was accompanied 4 h later by a partial recovery in the binding of 125I-[Tyr1]-SRIF to pituitary membranes. Passive immunoneutralization of endogenous SRIF resulted in a prompt (within 1 h) and sustained (for at least 24 h) suppression of 125I-[Tyr1]-SRIF binding to pituitary membranes. The i.m. administration of cysteamine (300 mg/kg) to 12-week-old birds depleted hypothalamic SRIF stores and decreased the density of 125I-[Tyr1]-SRIF-binding sites in the caudal and cephalic lobes of the chicken pituitary gland. The reduction in SRIF content and in SRIF-binding sites occurred within 1 h of cysteamine administration and was maintained for at least 24 h. In 6-week-old birds, cysteamine (300 mg/kg) administration suppressed pituitary binding of 125I-[Tyr1]-SRIF for at least 5 days. Circulating concentrations of GH were markedly decreased 1 and 4 h after cysteamine injection, but not after 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Somatostatin binding to chicken adenohypophysial membranes.

[125I-Tyr1]-Somatostatin (SRIF)-binding sites were demonstrated on crude plasma membrane preparations from chicken pituitary glands. These binding sites were saturable and of high affinity (dissociation constant less than 1.0 nM) and low capacity (maximal binding capacity less than 200 fmol/mg protein) and were specific for SRIF moieties. The number and affinity of these binding sites in the caudal lobe of the pituitary, in which somatotrophs predominate, were similar to those in the cephalic lobe, in which lactotrophs and thyrotrophs are confined. Gonadotrophs are present in the caudal lobe, but whereas exogenous SRIF inhibited secretagogue-induced GH release from incubated pituitary glands, it had no effect on basal or secretagogue-induced LH release. The half-maximal binding of SRIF to the caudal lobe membranes (3 nM) was similar to that required for half-maximal suppression of TRH-induced GH release, suggesting a role for these binding sites in the regulation of GH secretion in birds.

Growth hormone-binding sites in chicken hypothalamus.

Specific binding of 125I-labelled recombinant DNA-derived chicken GH (rcGH; 2.1 +/- 0.41 (S.E.M.) % of total counts) and of 125I-labelled bovine GH (1.80 +/- 0.27% of total counts) to crude plasma membranes of the chicken hypothalamus was demonstrated. Binding of 125I-labelled rcGH was related to the amount of tissue incubated and was significant over the range 250-950 micrograms membrane protein per tube. Binding of 125I-labelled rcGH was saturable over the range 0.14-0.40 pmol and was to a single class of high-affinity (33.5 pM) low-capacity (2.14 fmol/mg protein) binding site. Binding of 125I-labelled rcGH was displaced by ovine GH and by ovine prolactin. These results demonstrate, for the first time, central GH-binding sites in a vertebrate species.