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Abstract

Objective To examine the effects of short-term cyclic stretch on apoptosis in alveolar type II cells (A549). To study in vitro the direct influence of alveolar type II cells on mechanical stretch. Methods A549 were treated with different doses of lipopolysaccharide (LPS), 0 ng/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1000 ng/ml, and then A549 were lengthened 5%, 15%, 30% using a FLEXCELL tension unit 4000, a vacuum-driven device that applies strain to cells, which were cultured in six-well plates coated with collagen-I, and 12 cycles/min for 4 hours. Apoptosis was measured using the flow cytometry method that measures annexin V and propidium iodide (PI) staining. The morphological changes of apoptotic cells were observed by transmission electron microscope. Results Apoptosis could be induced in alveolar type II cells (A549) by mechanical stretch. The percentage of annexin V + PI cells increased after being treated with cyclic stretch for 4 hours by 5%, 15%, 30% in all groups. The morphological features of apoptotic cells demonstrated by transmission electron microscope were as follows: shrinkage of the cell, chromatin condensation and aggregation under the nuclear membrane as a crescent or lump, membrane-encapsulated nuclear fragment or cell organ formed by invagination of the cell membrane, and apoptotic body formation followed by vacuolization. Conclusion Apoptosis induced by mechanical stretch and LPS is dose dependent. Mechanical stretch aggravates apoptosis especially in cells treated with LPS. Annexin V and PI double staining is a specific, sensitive, and quantitative method for analyzing apoptotic cells. It is also helpful to clarify the protective mechanism of low-volume ventilation in ARDS. Acknowledgement The study was funded by the 'One Hundred People' project of Shanghai Sanitary Bureau (03-77-20).

Geriatric neuroanesthesia: the retrospective study of 158 patients

“…Anestezi ve cerrahi tekniklerin ilerlemesi ile birlikte daha çok sayıda yaşlı hastaya majör elektif ve acil cerrahi işlem uygulanmakta, bu nedenle yaşlı-ların yaşam süreleri uzamaktadır (1). Geçmişte, 65 ve üzeri yaşın cerrahi için bir kontrendikasyon olduğuna inanılmakta idi.…”

“…Risk faktörleri uygun şekilde yönetilen nörocerrahi vakalarında yaşın tek başına bir engel olmadığı belirtilmektedir. Kronolojik yaş, perioperatif komplikasyon riskleri açısından biyolojik yaşa oranla daha az önem taşımaktadır (1)(2)(3)(4). Yaşlı hastalar hala erişkin cerrahi nüfusun en yüksek mortalite ve morbidite oranına sahiptir.…”