We succeeded in visualizing in vivo perialveolar microcirculation and individual alveolar respiration in rats, by our high resolution intravital charge-coupled device videomicroscopy system.To elucidate the relevance and usefullness of our methods, we investigated their behavior 1) under control conditions, 2) during increased tidal volumes (TV), 3) during positive-end expiratory pressure (PEEP) application, and 4) during exposure to hypoxia. We recognized a sheet-like flow pattern in capillaries, and observed semi-collapsed capillaries at end-inspiration while flow continued. The latter indicate existence of“vascular waterfall phenomenon”. When TV was increased from 2.5 to 5ml, the alveolar size was increased from 30±10 to 65±18μm (n=21, p<0.05), and the red blood cell velocities in perialveolar capillary were significantly decreased from 910±210 to 290±140μm/sec (n=21, p<0.05). Following PEEP application with TV of 5ml, the alveolar diameter was increased even more to 80±20μm (n=12, p<0.05) and the flows of microvessels stopped temporarily at end-inspiration. We also visualized that precapillary arterioles clearly constricted from 34±6 to 28±6μm in response to hypoxia (n=9, p<0.05).In conclusion, the intravital pencil lens-probe videomicroscopy can be a powerful tool for in vivo observation of perialveolar microcirculation and alveolar respiration under important physiological conditions such as changing TV, application of PEEP, and exposure to hypoxia.
We describe two cases of adult-onset Schonlein-Henoch purpura with gastrointestinal manifestations. Case 1: A 73-year-old man was admitted to our hospital because of abdominal pain, diarrhea and fever. On physical examination, the abdomen was normal, and there were many palpable petechial hemorrhages on the lower extremities.Skin biopsy revealed infiltrations of lymphocytes, neutrophils and eosinophils into the dermis. A computed tomographic (CT) scan of the abdomen disclosed thickening of the intestinal wall in the duodenum and jejunum.Upper gastrointestinal fiberscopy revealed petechiation on the stomach and erosions on the duodenum. Case 2: A 54-year-old man was admitted to our hospital because of hematochezia.The patient had pharyngitis 4 days before admission, and his serum anti-streptolysion O level was increased.On physical examination, there were faint purpuras on the lower extremities.Skin biopsy revealed a histological image of leukocytoclastic vasculitis.A CT scan of the abdomen disclosed thickening of the intestinal wall in the duodenum, jejunum and ileum.Gastrointestinal fiberscopy revealed petechiation on the stomach and ulceration on the cecum.