[The Pathogenesis of Pulmonary Emphysema - Laennec was right!]

Pulmonary emphysema is characterised by irreversible destruction and enlargement of alveolar structure distal to terminal bronchioles. Small conducting airways < 2 mm in diameter are the major site of chronic airway inflammation and obstruction in COPD patients. 80 - 90 % of the last generation of small conducting airways, the terminal bronchioles, are destroyed in patients with very severe COPD. Recent data showing, that small airways disease is also a pathological feature in patients with COPD GOLD stage 1 and 2. Although 40 % of terminal and 60 % of transitional bronchioles were destroyed, there was no sign for emphysema. Only a significant loss of terminal and respiratory bronchioles seems to be able to induce pulmonary emphysema and respiratory symptoms.

Higher predation risk for insect prey at low latitudes and elevations

Biotic interactions underlie ecosystem structure and function, but predicting interaction outcomes is difficult. We tested the hypothesis that biotic interaction strength increases toward the equator, using a global experiment with model caterpillars to measure predation risk. Across an 11,660-kilometer latitudinal gradient spanning six continents, we found increasing predation toward the equator, with a parallel pattern of increasing predation toward lower elevations. Patterns across both latitude and elevation were driven by arthropod predators, with no systematic trend in attack rates by birds or mammals. These matching gradients at global and regional scales suggest consistent drivers of biotic interaction strength, a finding that needs to be integrated into general theories of herbivory, community organization, and life-history evolution.

[Apnea Detection by Means of Respiratory Sound Recordings and Polysomnography - A Comparative Study]

Introduction In this study, recognition of apnoeas by means of polysomnography (PSG) and nocturnal respiratory sound recordings in patients with obstructive sleep apnoea (OSA) was analyzed and compared. Methods In 45 patients with OSA requiring treatment (AHI > 15/h), concomitant polysomnographic recordings and long term respiratory sound recordings by means of LEOSound were performed. Patients' average age was 58 ± 12 years (mean ± standard deviation), average BMI was 33 ± 7 kg/m². Audio-visual apnoea detection by LEOSound was compared to polysomnographic apnoea detection. Increased artifact rate due to dislocation of microphones led to rejection of 11 out of 45 recordings for detailed analysis. Results Comparison of apnea detection by audio-visual analysis and polysomnography yielded a median of 164 apneas for LEOSound recordings and 158 apneas for PSG. Median apnoea index (AI) was calculated to be 20/h for respiratory sounds recording and 21/h for PSG. The correlation of apnea indices from acoustic long term registration and PSG was 0.939 (p < 0.001). Discussion Acoustic long term registration of primary and secondary respiratory sounds is also capable to recognize apnoeas. Exact differentiation between apnoeas and hypopnoeas is only possible in a limited fashion.

[Normal and Adventitious Breath Sounds]

Auscultation of the lung is an inexpensive, noninvasive and easy-to-perform tool. It is an important part of the physical examination and is help ful to distinguish physiological respiratory sounds from pathophysiological events. Computerized lung sound analysis is a powerful tool for optimizing and quantifying electronic auscultation based on the specific lung sound spectral characteristics. The automatic analysis of respiratory sounds assumes that physiological and pathological sounds are reliably analyzed based on special algorithms. The development of automated long-term lungsound monitors enables objective assessment of different respiratory symptoms.

[LEOSound, an innovative procedure for acoustic long-term monitoring of asthma symptoms (wheezing and coughing) in children and adults]

Particularly in young children the diagnosis of asthma is difficult and mostly based on clinical symptoms like wheezing, cough and dyspnea. Children with nocturnal wheezing often suffer from a low quality of sleep and impaired sense of well-being during the day. Physicians recommend that parents record the frequency of asthma attacks or symptoms to help manage their children's disease. The lack of an appropriate method for standardized and objective monitoring makes asthma management difficult. The aim of this paper is to present a new method for automated wheeze and cough detection and analysis. The mobile LEOSound recording and analysing system described here should help improve diagnosis and monitoring of asthma symptoms in children.

Formation of cytosine arabinoside-5'-triphosphate in different cultured lymphoblastic leukaemic cells with reference to their drug sensitivity

The accumulation of intracellular cytosine arabinoside-5'-triphosphate (Ara-CTP) is determined in five lymphoblastic cell lines: Molt 4, H9 and three newly established cell lines from paediatric patients, KFB-1, KFB-2, KFT-1. The cell lines KFB-1 and KFB-2 are B-lymphoblastic (B-ALL), the others are T-lymphoblastic leukaemic cells (T-ALL). The Ara-CTP levels were compared with the sensitivity of the cells to Ara-C. The cells were incubated at different concentrations (100 nM-100 microM) of Ara-C for 4 h or incubated for variable times (30 min-11 h) at 0.1, 1 and 10 microM Ara-C to form Ara-CTP. The Ara-CTP-concentrations were measured by high pressure liquid chromatography (HPLC). To determine the sensitivity of the cells to Ara-C, the MTT colorimetric-assay was used. The studies indicate that different B- and T-lymphoblastic leukaemia cell lines accumulate Ara-CTP to a markedly different extent. Ara-CTP plateau levels and sensitivity of the cells to Ara-C correlated well in four of the five cells lines studied.

Decreased anti-human immunodeficiency virus type-1 activities of 2',3'-dideoxynucleoside analogs in MOLT-4 cell sublines resistant to 2',3'-dideoxynucleoside analogs

Human T-lymphoid MOLT-4 cells were grown continuously for more than 1 year in medium containing either 3'-azido-2',3'-dideoxythymidine (AZT), 2',3'-dideoxyinosine (ddI) or 2',3'-dideoxycytidine (ddC) at concentrations similar to peak plasma levels found in clinical trials in patients with AIDS. To test antiviral activities of the nucleoside analogs against HIV-1 in the cell sublines designated MOLT-4r-AZT, MOLT-4r-ddI and MOLT-4r-ddC, the number of infected cells, p24 HIV-1 antigen in culture medium and syncytium formation of infected cultures were determined. The results showed that anti-HIV-1 activities of AZT, ddI and ddC were significantly decreased in the resistant MOLT-4 cell sublines grown continuously with the respective nucleoside analog, probably due to the development of cell populations resistant to the drugs.

In vitro differentiation of human neuroblastoma cells induced by sodium phenylacetate

Sodium phenylacetate (NaPA) at concentrations ranging from 2 to 6 mM stimulated morphological differentiation of two human neuroblastoma cell lines IMR-32 and UKF-NB-3. These concentrations inhibited growth and DNA synthesis of the cells in a dose dependent manner without significant effect on cell viability. The differentiated cells showed pseudoganglia formation and extension of cellular processes. The morphological differentiation in both cell lines was accompanied by decreased expression of N-myc oncoprotein. These results suggest that NaPA at concentrations, which have been achieved in humans with no significant adverse effects, promotes differentiation of cultured human neuroblastoma cells in association with the reduced expression of the malignant phenotype.

Aphidicolin selectively kills neuroblastoma cells in vitro

Aphidicolin is a tetracyclic diterpene antibiotic which is known to inhibit the growth of eucaryotic cells by reversible binding to DNA polymerase alpha without significant effect on cell viability in most common human cell lines. We observed that aphidicolin at a concentration of 5 x 10(-7) M kills all cells of four human neuroblastoma cell lines. In contrast, viability of normal human embryonal cells and of human continuous cell lines including HeLa, H9, A549 and Caco-2 was influenced only moderately by aphidicolin. In addition, neuroblastoma cells were killed after treatment with 5 x 10(-7) M aphidicolin in cocultures with normal embryonal cells which continued to proliferate after removal of aphidicolin. These results show that aphidicolin provides an agent which selectively kills neuroblastoma cells in vitro.