Pharmacology of the developing digestive system.
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Retrospective evaluation of 158 patients with digestive system neoplasms was carried out. The disease pattern was compared to that noted in other parts of Arabia, other Middle East countries, Africa, and the West. An attempt was made to analyze potential aetiological factors in the Saudi population. At all cancer sites of the digestive system the male to female ratio was 3:1. Generally more younger patients with advanced cancer were encountered than reported in series from the Western hemisphere. The poor results of therapy were generally attributed to the advanced stage at presentation. The high frequency of GIT cancer and in particular the apparently rising incidence rate of colorectal cancer was attributed to dietary habits and the changing lifestyle of the population. Hepatitis B viral infection was the likely cause of primary hepatocellular cancer (PHC) although dietary factors could not be ruled out. Schistosomiasis was found not to play a role in the causation of either PHC or colorectal cancer.
The morphometric analysis of growing cells shows that the membranes of the digestive apparatus have a surface area equal to the cell surface area. After yeast phagocytosis, the surface area of the membrane surrounding the ingested yeast is equal to 40% of the surface area of the cell membrane. In spite of this internalization, the cell surface remains constant. Its renewal is insured by the translocation of the membrane of the digestive system, the surface area that concomitantly decreases by 40%. This means that the influx of plasma membrane is continually compensated for by the same outflow of internal membranes. During this turnover, the characteristic polysaccharide stainability (two different stains were used) of the plasma membrane is maintained after internalization, at the level of the digestive system, despite the presence of hydrolases in the digestive vacuoles. The cytochemical demonstration of acid phosphatase shows that this enzyme penetrates into phagosomes by fusion between phagosomes and vacloles of various sizes. The debris of digested yeast are released into the culture medium after 2 h. This process of defecation is accompanied by the appearance of new pinocytotic vacuoles, which indicates that the uptake of axenic medium has resumed. A model of membrane turnover is proposed to explain these observations.
The distribution and characterization of calcitonin gene-related peptide immunoreactivity in the digestive system of normal, capsaicin-treated, and littermate control rats were studied by radioimmunoassay, chromatography, and immunohistochemistry. The highest concentrations of calcitonin gene-related peptide immunoreactivity were found in the stomach (45 +/- 2.8 pmol/g wet wt, nonsecretory region; 38.7 +/- 4.4 pmol/g wet wt, secretory region) and rectum (30.9 +/- 1.6 pmol/g wet wt). Significant amounts of peptide were also found in the other regions of the gut and in the pancreas. Neonatal treatment with capsaicin, which causes a permanent degeneration of most of the small-diameter sensory neurons, reduced calcitonin gene-related peptide content by greater than 95% in the esophagus and stomach, by 60% in the pancreas, and by less than 50% in the intestine, when compared with littermate controls. Separation of extracts from the gut, pancreas, and brain by chromatography gave major peaks corresponding to the predicted rat calcitonin gene-related peptide and small unidentified peaks, which presumably arise from metabolism of the peptide. Immunohistochemical studies demonstrated that in the esophagus and stomach, calcitonin gene-related peptide immunoreactivity is restricted to nerve fibers, whereas in the intestine it is localized in both nerve fibers and enteric ganglion cells. In capsaicin-treated rats there was a virtually complete elimination of calcitonin gene-related peptide immunoreactive fibers innervating the esophagus and stomach, whereas in the small and large intestine there was a dramatic reduction and often a complete elimination of those associated with blood vessels and a slighter reduction of the nonvascular immunoreactive fibers. The results of this study indicate that calcitonin gene-related peptide immunoreactive nerve fibers innervating the rat digestive system originate from both intrinsic (enteric) and extrinsic (presumably sensory) sources and that both the intrinsic and extrinsic components appear to contain a substance that corresponds to the predicted calcitonin gene-related peptide.
The pattern of nerve cells and fibers containing calcitonin gene-related peptide immunoreactivity (CGRP-IR) was investigated in the canine digestive tract by means of immunohistochemistry. CGRP-IR nerve fibers innervate all the layers of the gut, including the vasculature, with different densities depending on the region. CGRP-IR processes are sparse in the esophagus and stomach, where they are mostly confined to the enteric plexuses and vasculature. CGRP-IR fibers are quite abundant in the small and large intestine, where they form dense arborizations in the mucosa, and are numerous in the muscularis mucosae, deep muscular plexus and circular muscle. The myenteric and submucous plexuses of the intestine contain dense networks of CGRP-IR fibers and numerous CGRP-IR ganglion cells. On the other hand, in the enteric ganglia of the esophagus and stomach, in the intrapancreatic ganglia and in the ganglionated plexus of the gallbladder, CGRP-IR is restricted to non-varicose processes. A moderate density of CGRP-IR fibers supplies the endocrine and exocrine pancreas, and the fibromuscular layer and lamina propria of the gallbladder. The density of CGRP innervation in different regions can be summarized as follows: intestine >> pancreas and gallbladder > or = antrum > cardia > gastric corpus and distal esophagus. CGRP- and tachykinin (TK)-IRs are colocalized in a substantial population of fibers, particularly those distributed to the mucosa, muscularis mucosae and vasculature, whereas there was no evidence of colocalization in intrinsic ganglion cells. The present results suggest that (1) the CGRP innervation of the dog digestive system includes an intrinsic and an extrinsic component, and (2) CGRP- and TK-IRs are co-expressed in extrinsic nerve fibers. These findings extend previous observations in rats and guinea pigs and provide insights into the sites of action of CGRP in the digestive system of the dog, which has served as a model for CGRP functional studies.
PURPOSE: There are several methods of achieving endoscopic hemostasis of hemorrhage in the upper digestive system. We compared the therapeutic results and advantages of using a local injection of fibrin adhesive for endoscopic hemostasis, which we have found more effective than other hemostatic methods. METHODS: Between October 2000 and April 2002, 16 patients with hemorrhage in the upper digestive system underwent endoscopic hemostasis using fibrin adhesive. The hemorrhage was caused by a hemorrhagic tendency from liver disease, anticoagulant therapy, or failed hemostasis with clipping or local ethanol injection. The fibrin adhesive was injected through a standard 21-gauge endoscopic needle using the so-called sandwich method. RESULTS: Hemostasis was successfully achieved by a single local injection of fibrin adhesive, in all except one patient who had been on anticoagulant therapy for a long time and needed an additional local injection of fibrin adhesive. CONCLUSION: Fibrin adhesive does not cause any tissue injury, and a sufficient amount can be injected endoscopically even in patients with liver dysfunction and those on anticoagulant therapy. Thus, we think that endoscopic hemostasis with fibrin adhesive is safe and effective.
The analysis of the action of various anthelmintics on the integuments and digestive system of Strongylate nematodes indicated that all the used agents caused varying structural disorders. The swelling of the cuticle and its detachment from the subcuticle occurred with the overwhelming majority of the anthelminths on the integuments of the Strongylate nematodes. The digestive system showed an ample epithelial vacuolation in the intestinal wall, as well as swelling and destruction in the mitochondria and endoplasmic reticulum. Almost all the used agent lowered the levels of glycogen and RNA in the tissue of Strongylate nematodes.
This paper presents a novel microfluidic DNA digestion system incorporating a high performance micro-mixer. Through the appropriate control of fixed and periodic switching DC electric fields, electrokinetic forces are established to mix the DNA and restriction enzyme samples and to drive them through the reaction column of the device. The experimental and numerical results show that a mixing performance of 98% can be achieved within a mixing channel of length 1.6 mm when a 150 V/cm driving voltage and a 5 Hz switching frequency are applied. The relationship between the mixing performance, switching frequency, and main applied electric field is derived. It is found that the optimal switching frequency depends upon the magnitude of the main applied electric field. The successful digestion of lambda-DNA using Eco RI restriction enzyme is demonstrated. The DNA-enzyme reaction is completed within 15 min in the proposed microfluidic system, compared to 50 min in a conventional large-scale system. Hence, the current device provides a valuable tool for rapid lambda-DNA digestion, while its mixer system delivers a simple yet effective solution for mixing problems in the micro-total-analysis-systems field.
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In space flights of various duration, the gastropancreatic complex turned out to be the most liable part of the digestive system. The main changes occurring in the gastrointestinal tract involve an increase in the peptic gastric potential, pancreatic hyperenzymemia, change of the glycemic curve forms, a decrease in the liver and pancreas density.
Experiments were conducted to determine the effect of cropectomy on the total amount and calcium content of ingesta in the digestive tract of the laying hen at night, as well as to determine if any abnormal physiological changes had occurred in the cropectomized hens. Treatments were cropectomized, sham operated and unoperated control hens. The gizzards from cropectomized hens contained about twice as much feed at 7:30 p.m. as that of the controls. The gizzard weight, without contents, was also significantly heavier in cropectomized hens than that of the controls. At 7:30 p.m. total contents of the digestive system of cropectomized and control hens were 15.94 gm. versus 24.07 gm., respectively. The control birds also had 2.71 times more total calcium in the digestive system at 7:30 p.m. than the cropectomized birds. The contents of the small intestine of cropectomized birds had 17% more calcium at 7:30 p.m. than did that of the controls. However, by 5:30 a.m. the contents of the small intestine of the control birds had 3.17 times more calcium than did that of the cropectomized birds. No differences were found between treatments or between time periods in relation to tibia breaking strength, calcium content of tibia or percent tibia ash. The degree of dietary calcium deficiency at night appears to be greater with cropectomized hens, even though the gizzard compensates, in part, for the loss in storage capacity of the crop. It is hypothesized from these data that the crop is an important and necessary organ in the laying hen for supplying nutrients throughout the night when the hen is not consuming feed.
The risk of developing a second primary cancer was evaluated in approximately 64,000 persons diagnosed with cancer of the digestive system in Connecticut during 1935-82. Significant excesses of all second cancers combined were observed following cancer of the esophagus (58 observed vs. 33 expected), small intestine (41 vs. 24), and colon (2,268 vs. 1,714). A slight excess of multiple primaries was observed following cancer of the liver and biliary tract (47 vs. 40). The observed number of second cancers was nearly equal to the expected number for persons initially diagnosed with cancers of the stomach (251 vs. 258), rectum (952 vs. 941), and pancreas (40 vs. 40). Persons with initial cancers of the small intestine, colon, and rectum also had excess second cancers arising primarily in the colon, which suggested the influence of common etiologic factors or possibly misclassified metastases in some. Shared dietary, socioeconomic, or hormonal factors may explain the excess of uterine and ovarian cancers among patients with colon cancer and the excess of breast cancer among patients with colon and rectal cancers. Oral and respiratory cancers occurred more frequently than expected in persons with an initial esophageal cancer, which is likely due to common risk factors of cigarette smoking or alcohol intake, or both. The elevations in cancer of the prostate among males with cancers of the esophagus, small intestine, colon, rectum, liver/biliary, and pancreas are probably artifacts associated with increased medical surveillance of cancer patients. The prostate cancer excesses were limited to the first year after diagnosis of the initial cancer or decreased over time for all but cancer of the colon and small intestines. Increased medical surveillance may also contribute to the excess renal and bladder cancers seen within 5 years of diagnosis of stomach cancer. Excesses were also seen for second pancreatic cancer among small intestine and liver/biliary cancer patients and second kidney and brain cancers among those with colon cancer. The deficits of stomach and rectal cancer among persons initially diagnosed with the same tumors, respectively, were anticipated because surgical removal of the organ is the primary form of treatment. Patients with rectal cancer also had deficits of stomach and pancreatic cancers. Future research should clarify the role of diet, alcohol, metabolic and endocrine factors, and host susceptibility on the risk of second neoplasms following cancer of the digestive system.
OBJECTIVE: To study the differential expression and possible role of MLRQ subunit gene of nicotinamide adenine dinucleotide reduced (NADH) oxidoreductase in malignant tumors of digestive system. METHODS: Specimens of cancerous tissues and matched adjacent normal tissues resected during operation or biopsy: 38 pairs of specimens of esophageal carcinoma, 7 pairs of specimens of cardiac carcinoma, 14 pairs of specimens of gastric carcinoma, 11 pairs of specimens of colon carcinoma, and 7 pairs of specimens of liver carcinoma underwent PCR test and Northern hybridization to detect the differential expression of MLRQ subunit gene of NADH oxidoreductase. RESULTS: (1) Overexpression of MLRQ subunit gene was found in 31 of the 38 pairs of specimens of esophageal carcinoma (81.6%), 4 of the 7 pairs of specimens of cardiac carcinoma (57.1%), 12 of the 14 pairs of specimens of gastric carcinoma (85.7%), 4 of the 7 pairs of specimens of colon carcinoma (65.6%), and 7 of the 11 pairs of specimens of liver cancer (57.1%). No significant difference among different cancers was observed by X(2) test (all P > 0.05). (2) The up-regulation of MLRQ subunit was not correlated with clinic stage, infiltration degree, lymphatic metastasis, and differentiation of tumor (all P > 0.05). CONCLUSION: MLRQ subunit gene is up-regulated in the malignant tumors of digestive system.