Assessment of Efficiency of Repellent Formulations with N,N-diethyl-m-toluamide in Laboratory Conditions.

The affinity of N,N-diethyl-m-toluamide) (DEET) for various polymers that are potential inert carriers (PEG, PVP, NaCMC, PAA) was studied. Mixtures of DEET and the polymers were prepared and analysed for DEET vapour release using head space analysis. Polyvinylpyrrolidone (PVP) showed the highest affinity for DEET. Several insect repellent formulations in the form of a hydrogel, an o/w cream and a stick were prepared with 5% w/w DEET and either 1% w/w or no PVP. The release of DEET from the formulations was investigated by Head Space gas-mass spectrometry at 32 degrees C. The degree of absorption of DEET through the skin was evaluated by applying these topical preparations to shaved rabbit skin and measuring DEET content in the blood samples by gas-mass spectrometry at various time intervals after application. Based on these results the pharmacokinetic parameters were determined. The minimum penetration of DEET through rabbit skin was obtained with a hydrogel containing PVP as a carrier. The biological efficiency of repellent formulations containing 5% DEET (w/w) was evaluated for repellency using the mosquito Aedes aegypti. The results demonstrated that the hydrogel formulation based on polyacrylic acid containing 5% DEET (w/w) supplemented with 1% PVP (w/w), could serve as a suitable vehicle for repellent preparations containing DEET.

[Pulmonary function in persons with kyphoscoliosis]. / Plucna funkcija kod osoba sa kifoskoliozom.

Pulmonary function in 25 patients with a severe degree of kyphoscoliosis was studied. Severe restrictive ventilatory insufficiency and hypoxaemic-hypercapnic respiratory failure were discovered. Isolated deformities of the vertebral column were diagnosed in 15 patients while ten patients, apart from diagnosed kyphoscoliosis, had associated chronic obstructive pulmonary diseases. Significant differences in pulmonary function impairment between these two groups, i.e. patients with associated chronic obstructive pulmonary disease, were observed. This indicates that associated pulmonary disease accelerates the development and course of respiratory failure. Respiratory blood gas analysis in 11 patients over the course of two years showed significant worsening of hypoxaemia and hypercapnia, which implies that in patients with kyphoscoliosis the disease has a rapid progression once the respiratory failure develops.

[Smoking and doctors]. / Pusenje duvana i lekari.

The smoking control greatly depends on the general public opinion against smoking. It depends on many factors including the important role of health workers, especially of physicians. The authors interviewed 229 doctors working in the Belgrade University Clinical Centre. They had to answer a WHO questionnaire. The results were as follows: 34% of smokers, 18% of ex-smokers (no significant difference between sexes), and 48% of non-smokers. In the group of smokers 46% tried to strop smoking, but unsuccessfully. In a 5-year period 9% will continue to smoke; 24% will stop smoking, and 66% intend to stop smoking. The reason for those who will stop smoking are their children to whom they wish to give a good example (77%). In the group of non-smokers the reason was their own health. However, the experience of physicians is a good example for their patients (79% of non-smokers and 59% of smokers). For prohibition of tobacco advertising are 78% of non-smokers and 64% of smokers. About 40% of smokers and 25% of non-smokers plead for the permanent raising of tobacco price as a decreasing factor in tobacco consumption. However, all agree with the need of placing a ban on tobacco sales to children. In conclusion, doctors should be at the head of the smoking control and fight against smoking.

[The importance of the transfer factor test in the diagnosis of pulmonary emphysema]. / Znacaj testa transfer faktora u dijagnostici emfizema pluca.

Physical examination, X-ray and lung function studies were performed in a group of 29 patients with chronic obstructive lung diseases. According to the diffusing capacity, patients were divided into two subgroups: one with normal and the other with decreased lung transfer-factor. Comparing the parameters of pulmonary function significantly more severe obstructive ventilatory insufficiency and greater lung hyperinflation were found in the subgroup of patients with decreased diffusing capacity. In this subgroup the collapsing type of flow-volume loop and X-ray signs of emphysema were present more frequently than in patients with normal lung diffusing capacity.