Tumour control in ion beam radiotherapy with different ions in the presence of hypoxia: an oxygen enhancement ratio model based on the microdosimetric kinetic model.

Few attempts have been made to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy, and systematic studies to evaluate the impact of hypoxia in treatment with the beam of different ion species are sorely needed. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates, and do not explicitly distinguish between the ion species and fractionation schemes. In this study, a new type of OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed. The model has been benchmarked with published in vitro data, HSG, V79 and CHO cells in aerobic and hypoxic conditions, for different ion irradiation. The model has been included in the simulation of treatments for a clinical case (brain tumour) using proton, lithium, helium, carbon and oxygen ion beams. A study of the tumour control probability (TCP) as a function of oxygen partial pressure, dose per fraction and primary ion type has been performed. The modelled OER depends on both the LET and ion type, also showing a decrease for an increased dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the investigated clinical case, a significant increase in TCP has been found upon increasing the ion charge. Higher OER variations as a function of dose per fraction have also been found for low-LET ions (up to 15% varying from 2 to 8 Gy(RBE) for protons). This model could be exploited in the identification of treatment condition optimality in the presence of hypoxia, including fractionation and primary particle selection.

Snoring: analysis, measurement, clinical implications and applications.

Snoring was described in literature even before medicine. Common definitions do not consider acoustic measurements of snoring. In this paper we discuss the main pathophysiological aspects of snoring and the snoring-sleep relationship as the generating mechanisms. Snoring can be analysed and measured by the following methods: 1) Leq-Equivalent Continuous Sound Level, which only quantifies noisiness, annoyance, and damage to the partner's and snorer's hearing; 2) Power Spectrum, with frequency values, formantic structure data and typical shape, which can help to distinguish simple snoring from heavy snoring with obstructive sleep apnoea syndrome (OSAS); 3) Linear Prediction Code (LPC) method, which can define the cross-sectional area (CSA) of the upper airways and which locates sites of obstruction. Simulated snoring analysis with LPC and with simultaneous fluoroscopy permits the definition of CSA and the identification of three snoring patterns: nasal, oral and oronasal. Snoring is an important sign of sleep-related breathing disorders (SRBD), of the upper airway resistance syndrome (UARS), and of the OSAS. Snoring is a symptom of nasal obstruction and is associated with cardiovascular diseases and nocturnal asthma as a trigger or causative factor; however, its acoustic features in these disorders are not well-defined. Home monitoring of snoring is very useful for epidemiology and is mandatory, together with heart rate and arterial oxygen saturation (Sa,O2), to screen SRBD.

A computer system for timing and acoustical analysis of crackles: a study in cryptogenic fibrosing alveolitis.

A system for recording and processing lung crackles is described. These are detected by a microphone on the chest wall and recorded simultaneously with flow rate, tidal volume and oesophageal pressure on a four-channel tape recorder. The sound signal is subsequently digitized by an analog-to-digital converter and processed by a minicomputer, using the Time Series Language and the fast Fourier transform algorithm. A preliminary study on seven patients with cryptogenic fibrosing alveolitis (CFA) confirms that crackles typically occur at the end of inspiration; timing seems to be well related to inspired volume and esophageal pressure. Inspiratory crackles of CFA have a well-defined waveform: it consists of a starting component and a damped oscillation, which probably depends on the resonant frequency of the lung. The crackle energy content is mainly concentrated in the frequency range between 100 and 2 000 Hz, the spectrum shape being determined by the energy distribution between the two components of the waveform. This recording and processing system gives more complete information about crackles than auscultation does, allowing their quantification and reproducibility. It may be used to compare crackles in different diseases, and may be simplified and standardized for routine clinical use as an additional noninvasive diagnostic technique.

Total selective deficiency of serum and secretory IgA associated with farmer's lung.

We present a case of total IgA deficiency associated with farmer's lung. The IgA deficiency is combined with the IgE one. IgA are absent both in the serum and in the bronchial secretions; they are present on the surface of B-lymphocytes, also after the enzymatic surface digestion and resynthesis test is performed. With intravenous perfusion of human gamma globulins, during repeated courses, IgA reach a normal level and exceed it, despite the IgA concentration in the perfused compound is very low and despite the fact that injected gamma globulins are not detectable with electrophoretic method. IgA never appear in the bronchial secretion. The association between both IgA and IgE deficiency, with this pulmonary disease, differential diagnostics, and therapeutical features, are discussed.

[Action of heparin on pulmonary lipids and alveolar surfactant in rabbits]. / Azione dell'eparina sui lipidi polmonari e sul surfactant alveolare di conigli.

The effect of subcutaneous 1000 IU/kg calcic heparin every 12 hr for 7 days on lung lipids and pulmonary surfactant was examined in 10 male rabbits weighing 2.5-3.5 kg. Comparison with an identical control group showed a decrease in phospholipids and lecithins in the lung homogenate extract and in the alveolar liquid bubble stability index. The difference in the means was highly significant (P less than 0.001) for all three parameters.

RDT with acetate-free bicarbonate buffered dialysis fluid: long-term effects on lipid pattern, acid-base balance and oxygen delivery.

Thirteen uraemic patients with hypertriglyceridaemia were treated for 9 months with acetate-free, bicarbonate containing dialysis fluid. With this treatment more physiological correction of acid-base balance and better tissue oxygenation were obtained. This fact can explain the better tolerance to treatment we have seen. In 9 of these patients triglyceride levels fell significantly on bicarbonate treatment; they shifted back to higher values after return to acetate dialysis. No changes were found in the other 4 patients.

[Allergological study of subjects with chronic rhinitis]. / Studio allergologico in soggetti affetti da rinite cronica.

The following parameters were considered in an allergological study of 362 subjects with chronic rhinitis unaccompanied by bronchial asthma: sex, age at onset, residence, familial allergy, personal history, season in which distrubances occurred, nasal polyps, concomitance of conjunctivitis, appear of chronic bronchitis, skin tests for dusts, vegetable fibres, skin derivatives, pollens and moulds. A positive allergometric response was noted in 60.77% and familial allergy in 30.93%. Skin manifestations were observed in 20.99%. Conjunctivitis was present in 55.24%, most of whom were skin-positive; nasal polyps were present in 4.69%, most of whom were skin-negative. 1.65% had chronic bronchitis. 79.54% of the skin-positive subjects were sensitive to pollens, 47.72% to "inhalants" (28.18% to household dust), and 30% to moulds.

[Allergological findings in rhinitis-asthmatic subjects]. / Indagini allergologiche in soggetti rinoasmatici.

A comparison was made between skin-positive and skin-negative subjects in an allergological study of 404 patients with rhinitis and asthma. The two diseases had appeared simultaneously in 52.72% of cases, while rhinitis had appeared first in 35.14%. Respiratory disturbances had occurred more frequently before the age of 30 yr in allergic subjects and between 20 and 50 yr in skin-negative subjects. Familial allergy was noted in 34% and a personal history of skin allergy in 21%. Associations with conjunctivitis, chronic bronchitis and nasal polyposis were noted in about 50%, 13% and 4% respectively. Nearly all skin-negative subjects had disturbances the whole year round, as did 47.67% of the skin-positives, while 36.53% of the latter had disturbances in spring and summer only. A positive reaction to at least one allergen was noted in 79.95%. Pollens were positive in 70.58%, dusts, vegetables fibres and skin derivatives in 66.25%, and moulds in 33.12%. The allergens used and the number of positives obtained with each are listed. It is felt that reaction to pollen should be investigated in such subjects, even when their symptoms are not sea sonal.

[Alveolar surfactant and experimental diabetes (protective action of citicoline)]. / Surfactant alveolare e diabete sperimentale (azione portettiva della citicolina).

Above normal or normal S.R. values (0,70-0,90) (S.R. = 0,81 +/- 0,11), were noted in 13 alloxaneinduced diabetic rabbits treated with CDP-choline, and decreased values (S.R. = 0,57 +/- 0,06) in 9 diabetic rabbits not so treated. This difference was statistically significant (P less than 0,001). The results show that CDP-choline can protect surfactant from damage caused by alloxane-induced diabetes. The most likely explanation is increased synthesis of dipalmitoyllecithin, by intervention of CDP-choline, as cofactor, on lipid metabolism in the lung.

[Alpha 1-antitrypsin in the blood and pleural effusion fluid]. / Alfa-1 antitripsina nel siero e nel liquido dei versamenti pleurici

Alpha-1 antitrypsin levels were determined in 27 pleural effusion liquids classified as transudates and exudates in accordance with the clinical and laboratory data, and in their respective blood samples. Absolute values proved insufficient to distinguish transudates from exudates, though they were capable of signifying and replacing the relative protein value. The relation between liquid: serum alpha-1 AT ratio and the liquid: serum proteins ratio was direct and highly significant. Along with the liquid: serum LAD and liquid: serum proteins ratios, the liquid: serum alpha-1 AT ratio enables transudates and exudates to be differentiated with certainty.