In this prospective study, the value of computed tomography (CT) in detecting bullae and bleb formation of the lung in 35 patients with primary spontaneous pneumothorax (PSP) has been determined. The ability of CT in the detection of bullae and bleb formation and fibrotic changes is compared with the chest film in PSP. CT showed pathological lung changes in 31/35 patients. In most cases, few (n < 5) and small blebs (i.e., < 2 cm in diameter) were found. In 16/35 cases, blebs ( < 2 cm) and bullae ( > 2 cm in diameter) occurred in the extra-apical region. Contralateral pathological changes were found in 23/35. Bullae ( > 2 cm) could be detected only in 6/35. In the chest film, bullae and blebs could be detected in 11/35 cases on the ipsilateral (in 2/35 cases not confirmed by CT), in 3/35 on the bilateral and in 4/35 only on the contralateral side. Thus, CT was proved to be of high value in the assessment of bullae and bleb formation in PSP compard with chest film. Negative pressure drainage was instituted as primary therapy. In a follow-up of 9.6 ( ± 5.7 SD) months, only early recurrences were noticed (n = 35). The rate of recurrences was 6/35 patients. The longer follow-up period (mean 31.7 ± 6.1 months) could be performed for 32 patients; 3 were lost. Additionally, 2 recurrences occurred. No correlation between recurrences and anatomical status (number, size and distribution of blebs/bullae) as assessed by CT was found. Differential treatment protocols on the basis of the initial findings do not appear to be warranted.

BackgroundExposure to horses can cause severe allergic reactions in sensitized individuals. The breed, American Bashkir Curly Horse is categorized as hypoallergenic, primarily due to reports of allergic patients experiencing fewer symptoms while handling this special breed. The possible reasons for this phenomenon could be lower allergen production and/or reduced allergen release into the air because of increased sebum content in their skin and hair compared to other breeds. Therefore, the aim of the current study was to compare different horse breeds in relation to allergen content in hair and airborne dust samples.MethodsIn total, 224 hair samples from 32 different horse breeds were investigated. Personal nasal filters were used to collect airborne dust during the grooming of 20 Curly Horses and 20 Quarter Horses. Quantitative analysis of all samples was performed using two newly developed immunoassays for the detection of horse dander (HD) antigens and the major allergen Equ c 1 and the commercial assay for Equ c 4. Results were analyzed using multiple linear regression models for hair samples and the Mann Whitney U test for airborne samples.ResultsHorse antigen and allergen levels differed up to four orders of magnitude between individual animals. Despite enormous variability, levels of HD antigen, Equ c 1 and Equ c 4 in hair were significantly related to the breed and gender combined with the castration status of male animals. Curly Horses had significantly higher concentrations of all three tested parameters compared to the majority of the investigated breeds (medians: 11800 μg/g for HD antigen, 2400 μg/g for Equ c 1, and 258 kU/g for Equ c 4). Tinker Horses, Icelandic Horses and Shetland Ponies were associated with approximately 7-fold reduced levels of HD antigen and Equ c 1, and up to 25-fold reduced levels of Equ c 4 compared to Curly Horses. Compared to mares, stallions displayed increased concentrations of HD antigens, Equ c 1 and Equ c 4 by a factor 2.2, 3.5 and 6.7, respectively. No difference was observed between mares and geldings. No differences in airborne allergen concentrations collected with personal nasal filters during grooming were found between Curly and Quarter Horses.ConclusionBreed and castration status had a significant influence on the antigen and allergen levels of horse hair. However, these differences were smaller than the wide variability observed among individual horses. Compared to other breeds, Curly Horses were not associated with lower allergen levels in hair and in air samples collected during grooming. Our approach provides no molecular explanation why Curly Horses are considered to be hypoallergenic.

Exercise-associated oxygen desaturation in severe chronic obstructive pulmonary disease (COPD) remains a topic of unknown prognostic and clinical relevance and of unknown therapeutic importance. Furthermore, exercise limitation in these patients is due to multifactorial interaction of respiratory, cardiac, circulatory and ‘peripheral’ mechanisms. For the evaluation of the role of the oxygen-dependent mechanisms of exercise limitation we studied 14 stable patients with severe COPD (FEV₁ 32% pred., FEV₁/VC 41%, thoracic gas volume of 180% pred.) and mean Pa O₂64 mm Hg by a stage 1 cycle exercise test during breathing room air (FiO₂ 0.21) and hyperoxic (FiO₂ 0.35) air. The measurements were performed by an open system using a low dead space valve (55 ml) measuring real-time breath by breath oxygen consumption (VO₂) via a differential oxygen sensor, expired carbon dioxide (VCO₂), ventilation (VE), oxygen pulse and oxygen saturation in both conditions. With FiO₂ 0.21 the mean exercise limitation was restricted to 37 ( ± 14) W and the VO₂ to 11.7 ( ± 2.4) ml/kg/min with peak oxygen desaturation of 86.4 ( ± 3.2). With FiO₂ 0.35 the patients achieved a significant increase of workload to 55 ( ± 12.4) W and of VO₂to 14.9 ( ± 2.9) ml/kg/min. Despite the complete abolition of exercise desaturation by FIO2 0.35 the mean peak ventilation of 261/ min ( ± 5.1) vs. 27 1/min ( ± 4.1) remained unaltered and therefore the restriction of the ventilatory pump limited the exercise ability. The effects of FiO₂ 0.35 occurred in these patients at submaximum exercise and may be related to reduction of ventilatory cost of energy and delayed onset of metabolic acidosis. We conclude that oxygen treatment in borderline hypoxemic COPD patients who desaturate in exercise is of substantial benefit because oxygen may diminish the generally excessive ventilatory cost of energy at submaximum exercise.

To test the hypothesis that so called hypoallergenic horses (Curly horses) allow horse allergic riders to ride again, we investigated 40 horse allergic riders in a period of 37 months. We tested these patients (pts.) by skin prick test (SPT) with different non-curly and Curly horses and studied the riding hours and horse brushing by measurements of peak expiratory flow (PEF) and Tiffeneau tests (FEV1) as well as peak nasal inspiratory flow (PNIF) over 12 months. The results in 37/40 pts. showed no relevant reactions of the lower airways or nasal flow. Only in 3/40 patients an initial significant fall of FEV1 was observed, reversed by a single inhalation of salbutamol and not repeated despite further riding contact. In contrast to other allergic events (e. g. baker's asthma) a further and regular contact with these horses abolished the mild allergic reactions of the start period of contact. This may be due to hypoallergenic properties of these horses, whose test material produces weaker reactions in the SPT than that of normal horses. After a period of three years, a loss of reactivity to normal horses could be confirmed in some of the riders. The tested purebreed Curly horses may be a suitable alternative for horse allergic riders if the methodological precautions of this study are followed.

A horse allergic rider completed 60 riding lessons on Curly Horses within six months. This rider has become clinically tolerant to normal horse breeds within this time. This case may indicate that riding and brushing ABCR Curly Horses after 60 riding hours facilitates tolerance induction. Our data indicate that this could be a valid alternative to the common recommendation to strictly avoid horse riding.