Environmental enrichment potentiates thalamocortical transmission and plasticity in the adult rat visual cortex

It has been demonstrated that the complex sensorimotor and social stimulation achieved by rearing animals in an enriched environment (EE) can reinstate juvenile‐like plasticity in the adult cortex. However, it is not known whether EE can affect thalamocortical transmission. Here, we recorded in vivo field potentials from the visual cortex evoked by electrical stimulation of the dorsal lateral geniculate nucleus (dLGN) in anesthetized rats. We found that a period of EE during adulthood shifted the input–output curves and increased paired‐pulse depression, suggesting an enhanced synaptic strength at thalamocortical terminals. Accordingly, EE animals showed an increased expression of the vesicular glutamate transporter 2 (vGluT‐2) in geniculocortical afferents to layer IV. Rats reared in EE also showed an enhancement of thalamocortical long‐term potentiation (LTP) triggered by theta‐burst stimulation (TBS) of the dLGN. To monitor the functional consequences of increased LTP in EE rats, we recorded visual evoked potentials (VEPs) before and after application of TBS to the geniculocortical pathway. We found that responses to visual stimulation were enhanced across a range of contrasts in EE animals. This was accompanied by an up‐regulation of the intracortical excitatory synaptic marker vGluT‐1 and a decrease in the expression of the vesicular GABA transporter (vGAT), indicating a shift in the excitation/inhibition ratio. Thus, in the adult rat, EE enhances synaptic strength and plasticity of the thalamocortical pathway associated with specific changes in glutamatergic and GABAergic neurotransmission. These data provide novel insights into the mechanisms by which EE shapes the adult brain. © 2010 Wiley‐Liss, Inc.     

Temporomandibular clinical exploration in Italian adolescents

Objective: This study investigated the prevalence of the signs and symptoms of temporomandibular disorders (TMD) among Italian adolescents.

Methods: The data were recorded from 567 subjects (246 males and 321 females; age range 11–19 years), grouped according to age and molar class relationship.

Results: Forty-four point one percent of subjects showed at least one sign or symptom of TMD, which were significantly more frequent in the 16–19 year-old group (52.9%) in respect to the 11–15 year-old group (39.8%) (χ ² = 8.78; p = 0.003). Signs and/or symptoms were about 1.6 times more frequent in subjects with Class II/1 malocclusion (χ ² = 13.3, p = 0.0003), mostly for TMJ sounds (χ ² = 1.444; p = 0.036). Myalgia was more frequent in females than in males (χ ² = 3.882; p = 0.049).

Conclusion: TMD signs and/or symptoms among Italian adolescents seem diffused (44.1%). Therefore, all adolescents should be screened thorough medical history and clinical examination.     

Lactate dehydrogenase and its isoenzymes in respiratory diseases in children]

Total Lactate Dehydrogenase (LD, EC 1.1.1.27) activity in serum and LD isoenzymes were quantified in 161 children (51 with pneumonia at the time of diagnosis, 60 hospitalized for asthma in acute period and 50 healthy subjects) to ascertain the relationship of these markers with injury of lung tissue. No statistical variations, between different groups in total activity, were found. Significantly decreased proportions of LD1 (p less than 0.000001) and of LD2 (p less than 0.000001) with simultaneous increase of LD4 (p less than 0.000001) and LD5 (p less than 0.000001) resulted in children with pneumonia, as to asthmatic or healthy subjects. Investigators conclude that LD should be determined in every patient with pneumonia because of the presence of a specific LD isoenzyme pattern.     

Chemotherapy with or without estrogenic recruitment in metastatic breast cancer. A randomized trial of the Gruppo Oncologico Nord Ovest (GONO)

BACKGROUND:: This phase III study was carried out to verify whether a kineticrecruitment induced with low doses of diethylstilbestrol (DES)could increase the antitumor activity of chemotherapy in patientswith advanced breast cancer. PATIENTS AND METHODS:: Two hundred fifty-eight women with metastatic breast cancerwere randomized to receive chemotherapy consisting of cyclophosphamide600 mg/sqm i.v., epidoxorubicin 60 mg/sqm i.v. and fluorouracil600 mg/sqm i.v. (CEF) on day 1 or DES-CEF (diethylstilbestrol1 mg orally days 1–3 CEF on day 4) every 21 days. Patientswere treated until progression or, if responsive, for a maximumof 10 courses. RESULTS:: There were no significant differences between the two treatmentarms in response rates (51.3% to CEF and 49.6% for DES-CEF);median progression-free survival (9.4 months for CEF and 11months for DES-CEF group) or median overall survival (17.3 and20 months for CEF and DES-CEF arms, respectively). Non-hematologicaltoxicities were superimposable in the two arm, while DES-chemo-therapywas more myelotoxic. CONCLUSIONS:: This trial confirms that chemotherapy preceded by estrogenicrecruitment is still in an experimental phase and that, at present,it has no role in clinical practice. Further research is neededto test the possibility of combining different mitogens in thelight of new information about breast cancer cell growth. estrogenic recruitment, metastatic breast cancer     

Resting metabolic rate, fat-free mass and catecholamine excretion during weight loss in female obese patients

The reduction in resting metabolic rate (RMR) during weight loss exceeds that accounted for by changes in body composition by 15%, suggesting that factors other than fat-free mass (FFM) explain the metabolic adaptation during food restriction in obesity. Our study aimed to establish if changes in the sympathoadrenal system activity, as inferred from an integrated measure such as 24 h urinary excretion of catecholamines, may play a role in the RMR adaptation observed during dietary restriction in obese patients. Ninety-three obese female subjects consumed a low-energy diet (LED) (2930 kJ/d (700 kcal/d)) for a 3-week period. At the beginning and at the end of the study, 24 h urinary excretion of catecholamines, FFM and RMR were measured. The LED induced a significant reduction in body weight (-3.3 (SEM 0.4) kg; P < 0.01), FFM (-1.9 (SEM 0.7) kg; P < 0.01) and in the fat mass (-1.2 (SEM 0.5) kg; P < 0.01). Noradrenalin excretion (24 h) decreased during the LED from 264 (SEM 26) during a weight-maintenance period to 171 (SEM 19) nmol/24 h after consumption of the LED for 3 weeks (P < 0.001); mean 24 h adrenalin excretion did not change during the LED (22 (SEM 3) during the weight-maintenance period v. 21 (SEM 3) nmol/24 h after consumption of the LED for 3 weeks; NS). The LED induced a significant decrease in RMR (7300 (SEM 218) v. 6831 (SEM 138) kJ/24 h; P < 0.001). The only independent variable that significantly explained variations in RMR both before and after consumption of the LED for 3 weeks, was FFM (r2 0.79 and r2 0.80 respectively). Urinary noradrenalin excretion explained a further 4% of the variability in RMR, but only before the diet, so that a role of sympathoadrenal system on RMR seems to be present in obese patients in basal conditions but not at the end of the LED.     

Double blind, placebo controlled study of nedocromil sodium in asthma

After a two week baseline, 209 asthmatic children (mean age 10 years, range 6-17) were randomly allocated to receive 4 mg nedocromil sodium (n = 110) or placebo (n = 99) four times daily for 12 weeks in addition to their current treatment. The children completed daily diary cards and visited the clinic at four week intervals. Statistically significant differences in favour of nedocromil sodium were seen for clinician assessment of asthma severity and diary card symptom scores, pulmonary function and inhaled beta 2 bronchodilator use. Total symptom score decreased by 50% from baseline in the nedocromil sodium group and by 9% in the placebo group during the final four weeks. Nedocromil sodium was considered very or moderately effective by 78% of children/parents (placebo 59%) and 73% of clinicians (placebo 50%). Nausea, headache and sleepiness, and dyspnoea led to withdrawal of one child from nedocromil sodium and placebo treatments, respectively. Reports of sore throat and headache were marginally greater with the nedocromil sodium treatment. It is concluded that nedocromil sodium was both effective and safe in the treatment of asthma in children.