[Reductive dechlorination of chlorophenols by an anaerobic mixed culture]

In this study, we investigated the potential for reductive dechlorination of chlorophenols by municipal sewage sludge acclimated to 2,4-dichlorophenol (2,4-DCP) and 3,4-dichlorophenol (3,4-DCP). The optimal temperature and pH for dechlorination of 2,4,6-trichlorophenol (2,4,6-TCP) were 30 degrees C and 7.2. Dechlorination of 2,4,6-TCP was inhibited by sulfate, nitrate, or ferric (III), but was increased by manganese (IV) except that product of 2,4-DCP was accumulated. Organic substrates such as pyruvate or acetate did not influence dechlorination of 2,4,6-TCP, but increased dechlorination of 2,4-DCP; nevertheless lactate showed no influence on dechlorination. When glucose was added as substrate, only 20% of 2,4,6-TCP dechlorination was found. Addition of methanogenesis inhibitor 2-bromoethane sulfonate did not influence dechlorination, but addition of eubacteria inhibitor vancomycin showed no dechlorination activity at the first few days, and finally complete transformation and accumulation of 2,4-DCP occurred. Because mixed culture was from Di-Hwa Wastewater Treatment Plant, adding the same water as culture medium was found to increase the dechlorination of 2,4,6-TCP and its product 2,4-DCP. Dechlorination by adding wastewater of Petroleum Corporation was also increased, especially for 2,4-DCP product, but only 7% of 2,4,6-TCP dechlorination was found after incubation with Hou-Chin river water for 14 days.

Transcription of carcinoembryonic antigen in normal colon and colon carcinoma. In situ hybridization study and implication for a new in vivo functional model

Recently carcinoembryonic antigen (CEA) has been functionally identified in vitro as a cell adhesion protein. Identification of its function in vivo requires knowing how CEA mRNA is transcribed in intact tissues. For this purpose, 16 cases of colon adenocarcinomas and autologous normal colon were studied by quantitative in situ hybridization for the expression of CEA mRNA. Normal colonic crypts displayed an upward gradient of mRNA expression. In colon carcinoma, tumor cells at the deep invading front of the tumor contain 2.6 times more CEA mRNA than tumor cells near the luminal surface. Immunoelectron microscopy showed intercellular CEA. In normal colon and colonic carcinoma, changes in CEA mRNA were paralleled by similar gradients in CEA protein, consistent with a transcriptional regulation of CEA expression. A new in vivo model of CEA function is presented to account for this overexpression of CEA occurring at sites characterized by changes in cell adhesion. The model requires that secreted CEA inhibits cell adhesion mediated by cell-bound CEA.

[A study of gastric mucosal blood flow of peptic ulcer, chronic gastritis and gastric carcinoma]

Gastric mucosal blood flow (GMBF) was studied in of 187 cases of peptic ulcer, chronic gastritis and gastric carcinoma with Laser Doppler Flowmetry (PF2). Results showed that GMBF in active ulcer (n = 68) was significantly slower than that in normal subjects (51.8% of normal value). GMBF in chronic atrophic gastritis (CAG) was significantly lower than that in chronic superficial gastritis (CSG). GMBF in gastric carcinoma was obviously slower than that in benign active ulcer as well as CAG and CSG. GMBF might be of help in the differential diagnosis of malignant or benign ulcer of stomach.

Post-stimulus depression of reflex changes in circular muscle activity in the guinea pig small intestine

The extent and time course of depression of successive reflex responses recorded with intracellular microelectrodes from the circular smooth muscle of the guinea pig small intestine were determined. Two stimuli were used, distension and distortion of the mucosa by compression; these were applied either at the same or at different sites. Excitatory responses oral and inhibitory responses anal to the stimuli were recorded. Post-stimulus depression of both ascending excitatory and descending inhibitory reflexes occurred, but the extent of depression was slightly less for the descending inhibition. A conditioning distension lasting 9 s depressed the excitatory response to a test distension applied 2 s later at the same site by 90%. After 30 s the depression was 50% and test responses were normal if inter-stimulus intervals were increased to 2 min. Increasing the duration of the conditioning stimulus increased the depression. Post-stimulus depression was less for compression stimuli than for distension stimuli and prior mucosal compression had almost no effect on responses to subsequent distension. The post-stimulus depression was greater if conditioning and test stimuli were at the same rather than different sites. For different sites, conditioning stimuli at 15 mm from the recording site (near) depressed responses to stimuli at 30 mm (far) to a greater extent than far stimuli depressed responses to near stimuli. If the conditioning stimulus at 15 mm was maintained until after the far test stimulus was applied, depression of the test response did not occur. It is concluded that the major sites of post-stimulus depression are at the synapses between primary sensory neurons and the first interneurons of reflex pathways, and that post-stimulus depression also occurs at other places in the pathway, presumably at synapses between interneurons or between interneurons and motor neurons.

Mucosal distortion by compression elicits polarized reflexes and enhances responses of the circular muscle to distension in the small intestine

The possibility that distortion of the mucosa by compression might be a sufficient stimulus to evoke reflex responses in intestinal muscle, and that such reflexes might summate with distension-evoked (stretch) reflexes, was tested in isolated segments of guinea pig small intestine. Opened segments of intestine were pinned flat in an organ bath with, or without, distending balloons embedded in its base. Intracellular microelectrode recordings were taken from the circular muscle oral and anal to sites of application of sensory stimuli. Pressure against the mucosa, which distorts the villi without the wall being stretched, evoked polarized reflex responses in the circular muscle, consisting of excitatory junction potentials oral and inhibitory junction potentials anal to the stimulus. Distension stimuli applied by 6-mm diameter balloons that pushed against either the serosal or the mucosal surface also evoked excitatory junction potentials in the muscle oral to the stimulus and inhibitory junction potentials at anal sites. Response amplitudes were 20% greater when the distending balloon pushed against the mucosal surface. Responses to distension from the serosal side were of 20% greater amplitude when combined with mucosal distortion by compression than without such compression. It is concluded that peristaltic movements that are commonly studied in the small intestine can be consequences of reflexes elicited at the same time from mucosal distortion receptors and from stretch receptors.

Interleukin-6 and its receptor are expressed in human intestinal epithelial cells

Recent studies have suggested that intestinal epithelial cells demonstrate some of the functions associated with immune competent cells. Based on these observations, we investigated whether gastrointestinal epithelial cells express Interleukin-6 (IL-6). The presence of this cytokine was tested in 53 normal and pathological tissue specimens of the human gastrointestinal tract using an immunohistochemical technique with anti-IL-6 monoclonal and polyclonal antibodies. Immunostaining shows that IL-6 is expressed in gastric and small intestinal epithelial cells. The tumor cells from a large subset (11 of 15) of colon cancer specimens were strongly immunostained. IL-6 immunostaining was less conspicuous and less frequent in the epithelial cells of normal colonic mucosa. Northern blot experiments indicated that the expression of IL-6 in colonic mucosa correlates quantitatively with the presence of its m-RNA. Furthermore, IL-6 receptor (IL-6R) m-RNA was also detected and was twice as abundant in colonic carcinoma as in normal colon. It is concluded that mucosal epithelial cells of the gastrointestinal system express IL-6 and that in the case of the colon, malignancy is accompanied by a higher expression. In addition, the presence of IL-6R transcript suggests that normal and neoplastic colonic epithelial cells might be autocrinally regulated by IL-6.

[Superficial blood flow (SBF) in 193 patients with traumatic paraplegia]

SBF in 15 regions (sacral spot and bilateral nail-fold, Zu-San-Li, San-Yin-Jiao, Tai-Xi, Xing-Jian, Guan-Yuan-Shu and femur) was measured by means of Laser Doppler Flowmeter in 193 patients with paraplegia resulted from trauma during the Tangshan earthquake, and the result was compared with that in 53 normal subjects. The results showed: (1) The SBF in region of the patients' limbs was more decreased than that in normal subjects (P less than 0.001). (2) There was also a declining of SBF in the right femur as compared with the normal (P less than 0.001). (3) The bilateral nail-fold blood flow in 55 patients with injury of vertebrae thoracales was significantly lower than that in 38 patients with lumbar vertebrae injury, indicating that having lived for 12 years since spinal cord injury, the patients still have microcirculatory disturbance over the whole body. Since SBF at the predilection site of decubital ulcer was decreased significantly more than that at non-ulcer site, it would be very important to improve local microcirculatory perfusion for prevention and treatment of decubital ulcer.

raf involvement in the simultaneous genetic transfer of the radioresistant and transforming phenotypes

We examined a human Alu+ mouse tertiary transformant derived from a noncancerous skin fibroblast cell line which exhibits the unique characteristic of being resistant to the killing effects of ionizing radiation. This transformed cell line was found to contain activated human c-raf-1, and demonstrated an increased level of radioresistance indicating the simultaneous transfer of both the transforming and radiation-resistant phenotypes. We have also found a relationship between the presence of activated oncogenes, specifically those with serine/threonine kinase activity and the radioresistant phenotype.

[Evaluation of antipyrine clearance in chronic liver diseases]

Antipyrine (AP) clearance was determined in 23 cases with liver cirrhosis (LC), 12 with chronic active hepatitis (CAH), 12 with hepatocellular carcinoma (mcHCC), 20 with non-hepatic diseases and 70 healthy controls. ICG Clearance was performed simultaneously in 9 cases of them. The results showed that AP clearance was significantly decreased in patients with LC and moderately decreased in CAH and HCC, its diagnostic sensitivity in LC was significantly higher than that of GPT. The significant positive correlation between the AP and ICG clearance was noted and AP clearance also well correlated with serum albumin level and prothrombin time. It is suggested that AP clearance may be used as a quantitative test to determine the reserve capacity of liver and as a substitutive test for ICG clearance.

The effects of high iodine on the brain development of mice

C57 mice were divided into two groups: (A): experiment group (H group). Each female mouse was injected with 20 microliter iodized oil; (B): control group (N group). Both groups were mated 8 days after iodized oil injection. Urine iodine contents/24 h of H group was 20 times higher than that in N group 7 days after injection and 18 times higher two months later. Serum T4 values were determined. Brain protein, DNA, body weight, motility and learning ability were measured in the progeny. The results indicate that there was no statistically significant difference between the groups in any of the parameters mentioned above. This strongly suggests that a high iodine dose, given as iodized oil, does not have obvious damaging effects on brain development, at least in mice.