The surface morphology and histogenesis of small intestine of human embryos (from 6 to 36 weeks) were studied by scanning electron microscopy and light microscopy. The results indicated that some low prominences began to form at 6 weeks of gestation and then transformed to round tuberculum, after that to polygonal column. The finger-like intestinal villi were formed finally at the end of 3 months. There was a apparent proximodistal gradient of the morphological maturation of villi and the histogenesis of intestine from duodenum, jejunum to ileum. Splitted and branched villi were found. From 18 weeks onward, the respective characteristics of villi in the three segments of small intestine appeared. Neutral mucus and sialomucus were mainly secreted by the goblet cells, while sulphomucus was secreted by the goblet cells of ileum during the late gestation. By 6-12 weeks the microvilli of duodenum were shorter than that of jejunum and ileum but they increased in height to 1.4?m at 18 weeks. The height of microvill at jejunum and ileum were 0.8-1.0?m from 14 weeks to 32 weeks. Tufts of thick and long microvilli among short microvilli were found. The formation of villi, secretion of goblet cells and microvilli was discussed.

Objective To analyze clinical and laboratory features, viral load and viral shedding period of patients with mild or severe H1N1 influenza A infection. Methods Seventy mild cases and 16 severe cases with concurrent pneumonia were included from Shcnzhen area for analysis.Nasopharyngeal-swab specimens of patients were collected and viral load was detected by real-time quantitative polymerase chain reaction (PCR) assay during their hospitalization. The viral load and viral shedding period were compared between patients over 14 years old and less than 14 years old, and between 70 mild cases without pneumonia and 16 severe cases with pneumonia. The statistic analysis was performed using t test and chi square test. Results The most common symptoms and signs of the patients were fever, cough and enlargement of tonsils. However, the severe cases suffered more frequently from cough, dyspnea and high fever compared with the mild cases (x2 = 10. 9 and 14.3, respectively, t=3.65; both P＜0.01 ). The levels of white blood cell (WBC) count and alanine arninotransferase (ALT) of severe patients were both significantly higher than those of mild patients(t= 3.2, 2.4,respectively; both P＜0.05). The chest radiology of the severe cases showed interstitial pneumonia,mostly with ground glass image. The viral load of patients under 14 years was significantly higher than those over 14 years [(4.86± 1.23) lg vs (4. 17±0.89) lg; t=2.3, P＜0.05], and the viral shedding period of patients under 14 years was significantly longer than those over 14 years [(5.33±0. 49) d vs(3. 63±0.28) d; t=3.4, P＜0.01]. The severe patients also displayed significantly higher viral load and prolonged viral shedding period than the mild patients [(6. 36±1. 44) lg vs (4. 35±0.99) lg, t=6.1,P＜0.01; (5.75±1.77) d vs (4. 24±1. 96) d, t=3.2, P＜0.01]. Conclusion Age anddisease severity of patients with H1N1 influenza A infection are significantly associated with viral load and viral shedding period.