A rat model for radiation-induced proctitis

Radiation proctitis is a frequent acute complication encountered with pelvic irradiation. This study was aimed at establishing the optimal radiation dose for radiation-induced proctitis in rats. Female Wistar rats were used. The rectal specimens were examined morphologically at 5th and 10th day following 10-30 Gy irradiation in single fraction. With increasing dose, mucosal damage became worse, and there was a prominent reaction after > or =15 Gy. We selected 17.5 Gy as an optimal dose for radiation proctitis and examined specimens at day 1-14 and at week 4, 6, 8, and 12 after 17.5 Gy. The rectal mucosa revealed characteristic histological changes with time. An edema in lamina propria started as early as 1-2 days after irradiation and progressed into acute inflammation. On day 7 and 8, regeneration was observed with or without ulcer. Four weeks later, all regeneration processes have been completed with end result of either fibrosis or normal appearing mucosa. This study showed that the radiation injury of the rectum in rat develops in dose-dependent manner as it has reported in previous studies and suggested that 17.5 Gy in single fraction is the optimum dose to evaluate the protective effect of various medications for radiation proctitis in face of the clinical situation.     

慢性乙肝患者杀伤性免疫细胞功能的研究

通过对４４例病毒性肝炎患者Ｔ细胞亚群，ＮＫ细胞活性与ＬＡＫ细胞活性的观察，探讨了在慢性乙型肝炎病毒复制与非复制状态下的杀伤性细胞活性。结果表明：在乙肝病毒的高复制状态下，ＣＤ８＾＋细胞数增加，ＣＤ４＾＋／ＣＤ８＾＋比例显著下降；ＮＫ细胞活性与ＬＡＫ细胞活性也明显低下，且在ＨＢｅＡｇ与ＨＢＶＤＮＡ阳性组中，ＮＫ活性与ＬＡＫ活性的改变与ＨＢｅＡｇ的Ｐ／Ｎ值变化呈显著负相关，而ＮＫ活性与ＬＡＫ活性变化则     

Negative pressure effects during the isothermal crystallization of isotactic poly(propylene) studied by light and atomic force microscopy

The formation of holes during the late stage of the isothermal crystallization in thin films of isotactic poly(propylene) between two cover glasses was observed by light microscopy and atomic force microscopy. This behavior can be described consistently by the well-known negative pressure effect. Light microscopy reveals the simultaneous and sudden occurrence of a large number of small holes at the liquid-solid interface after the liquid in front of the spherulites is completely confined by other spherulites for a certain time interval. In exceptional cases only a few holes appear and finally large cavities are formed. Atomic force microscopy measurements carried out in the height mode are able to prove the hole formation in front of the spherulites. Furthermore, a substantial thinning of the two-dimensional spherulites in thin films can be observed prior to the hole formation.     

Diastematomyelia--clinical manifestation and treatment outcome.

Diastematomyelia is a rare congenital anomaly characterized by a division of the spinal cord or the filum terminale into two parts. In Korea, only one case has been reported. The authors have operated on 5 cases of diastematomyelia with septum since July, 1978. The ages ranged from 1 to 44 years (median; 11 years). There were 2 boys, 2 girls and an adult man. The disease manifested by cutaneous abnormalities and neurological or orthopedic deficits. Pain was a chief complaint in the adult patient. The symptoms had progressed in 3 cases. The diagnosis was made correctly by CT myelography or MRI in 4 cases. The median septum was located at the lumbar area in 4 cases and at the lumbosacral region in 1 case. Associated abnormalities included low lying conus (5 cases), lipoma (2 cases), thickened filum terminale (1 case), hemilipomyelomeningocele (1 case) and syrinx (1 case). The median septum was removed. The dural sleeve adjoining the septum was resected and the dural sac was reconstructed. The role of MRI in the diagnosis and planning of surgery and the high frequency of associated low lying conus were emphasized. Though the surgical treatment relieved pain, it did not reverse the neurological deficits or orthopedic deformities significantly, which suggests the beneficial effects of early surgical intervention in the cases with progressive symptoms.     

Flat depressed early colon cancer--a case report.

A flat depressed early colon cancer (FDEC) is characterized by non-polypoid growth pattern, no association of adenomatous tissues and a tendency of even small lesions toward submucosal invasion and lymph node metastasis. It supports de novo carcinogenesis of colorectal cancer, although most colorectal cancers arise in pre-existing adenoma (adenoma-carcinoma sequence). There have been few reports of small depressed cancers because of the difficulty in colonoscopic detection and the rapid development to ulcerating advanced cancers. We report a case of flat depressed early colon cancer confined to mucosa detected by indigo carmine contrast colonoscopy.     

Studies on hypoxia. 8. Ultrastructural and biochemical effects of prolonged exposure on rat parotid glands

The effect of chronic hypoxia upon the rat parotid gland is studied by electron microscopy and biochemistry. Male Sprague-Dawley rats are subjected to 88% N₂ and 12% O₂ at less than 2 psi pressure for 7 days. For electron microscopy, the tissues are perfusion-fixed, embedded and sectioned in a routine manner. In the biochemical studies, rats are injected with ³H-phenylalanine (2 μCi/g; s.i. ～ 5 Ci/mM) 60 min before sacrifice. Fresh glands are then prepared for analysis of amylase (Cibachrome-amylase substrate method), DNA (diphenylamine reaction), and total protein (Lowry method). The radioactivity in the acid precipitable and soluble fractions is determined by liquid scintillation spectrometry. The control animals are pair-fed and handled identically except that they are maintained in an ambient atmosphere. The ultrastructure of the hypoxic cells is altered in several areas. The Golgi apparatus demonstrates a decrease in organization and contains fewer transport vesicles. The rough-surfaced endoplasmic reticulum is broken and presents many vesicular and concentric profiles. The mitochondria have undergone several changes including swelling, clumping of intramitochondrial matrix, and fragmentation of cristase. The nucleus demonstrates a fibrillar pattern and contains a reduced amount of heterochromatin. The biochemical results indicate that, compared with controls, the hypoxic cells contain only 55% of amylase and 84% of the DNA, and thus suggest a drastic reduction of exportable protein production and an increase in cellular size, respectively. On the contrary, the incorporation of ³H-phenylalanine demonstrates an increase in the amount of radioactivity in the acid precipitable fraction of the hypoxic cells. These results lead to the conclusion that hypoxic stress causes a suppression of exportable protein synthesis, but may induce other cytoplasmic protein production, reflecting the biochemical and morphologic adjustment of the cell to a recovery phase.     

音猬因子的功能受体斑片在培养神经干细胞中的表达

目的　观察在培养的神经干细胞内是否有发育调控分子———音猬因子 (sonichedgehog)功能受体———斑片 (patched)表达。　方法　神经干细胞克隆在体外培养传代后 ,用patched的特异性引物对培养的神经干细胞进行RT PCR分析 ,PCR产物经克隆测序后 ,用地高辛标记克隆的探针 ,对神经干细胞进行原位杂交分析。　结果　神经干细胞克隆内大量的细胞均可表达sonichedgehog的功能受体patched ,patched阳性细胞间未见明显差别 ,克隆边缘与中央的patched分布也未见明显差别。　结论　sonichedgehog信号传导路可能在神经干细胞的增殖与分化过程中起重要作用。     

周围神经干自然分束部位血管形态及临床意义

应用微血管灌注透明法观察研究5具成人周围神经干标本.重点观察神经自然分束部位微血管形态和分支分布规律.神经干内有非常完兽的血供系统.手术中循神经自然分束进行追踪分离,不会对神经血供产生明显影响.但在张力下牵拉缝合神经,将对神经干血供产生严重影响.神经束膜缝合比神经外膜缝合更强调在无张力下进行.     

Emphysematous lung destruction by cigarette smoke. The effects of latent adenoviral infection on the lung inflammatory response.

This study was designed to test the hypothesis that cigarette smoke-induced inflammation and emphysema are amplified by the presence of latent adenoviral (Ad) infection, and to determine whether this emphysematous process can be reversed by all-trans-retinoic acid (RA) treatment. The results confirm that in guinea pigs, chronic cigarette-smoke exposure caused lesions similar to human centrilobular emphysema. They also show that latent Ad infection combined with cigarette-smoke exposure caused an excess increase in lung volume (P < 0.001), air-space volume (P < 0.001), and lung weight (P < 0.01), and further decrease in surface-to-volume ratio (P < 0.001) compared with smoke exposure alone. RA treatment failed to reverse these emphysematous changes. Analysis of inflammatory response in parenchymal and airway tissue showed that smoking caused an increase of polymorphonuclear leukocytes (PMNs) (P < 0.0002), macrophages (P < 0.001), and CD4 cells (P < 0.0009), and that latent Ad infection independently increased PMNs (P < 0.001), macrophages (P = 0.003), and CD8 cells (P < 0.001). We conclude that latent Ad infection amplifies the emphysematous lung destruction and increases the inflammatory response produced by cigarette-smoke exposure. In this study, the increase in CD4 was associated with cigarette smoke and the increase in CD8 cells with latent Ad infection.