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Biomedical subjects

H Ernst

Publications and source records attributed to H Ernst.

At least 37 records · Page 2Linked to original sources
PubMed1997

Mucosal expression and luminal release of epidermal and transforming growth factors in patients with duodenal ulcer before and after eradication of Helicobacter pylori.

BACKGROUND: Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) are potent gastric acid inhibitors and stimuli of mucosal growth and protection but their involvement in Helicobacter pylori associated duodenal ulcer has been little examined. AIM: To assess gastric acid secretion, plasma gastrin concentrations, mucosal content of EGF and TGF alpha, and mucosal expression of these peptides and their receptor (EGFr) as well as salivary and gastric luminal release of EGF under basal conditions and after pentagastrin stimulation in 10 healthy subjects and in 25 H pylori positive patients with duodenal ulcer before and after two weeks of triple anti-H pylori therapy and four weeks after the termination of this therapy. RESULTS: Pentagastrin stimulation caused a significant increase in salivary and gastric release of EGF both in healthy controls and patients with duodenal ulcers but in the patients, the eradication of H pylori resulted in several fold higher gastric luminal (but not salivary) EGF release than before the anti-H pylori therapy. Mucosal contents of immunoreactive EGF and TGF alpha and mucosal expression of EGF, TGF alpha, and EGFr in H pylori positive patients with duodenal ulcer were significantly higher than those in healthy H pylori negative controls and this increase persisted after eradication of H pylori. Basal plasma gastrin was significantly reduced after two weeks of triple therapy and four weeks after the H pylori eradication all ulcers were completely healed. CONCLUSIONS: (1) H pylori infection in patients with duodenal ulcer was accompanied by enhanced plasma gastrin and increased mucosal content and expression of TGF alpha, EGF, and EGFr; (2) H pylori eradication resulted in ulcer healing, reduction in plasma gastrin, and enhancement of gastric (but not salivary) luminal release of EGF, particularly after pentagastrin stimulation; and (3) enhanced mucosal content and expression of TGF alpha, EGF, and EGFr and increased luminal release of EGF may contribute to ulcer healing after eradication of H pylori.

Duodenal Ulcer↗
PubMed1997

Investigations on health-related properties of two sepiolite samples.

Published i.p. injection studies have shown different biological behavior of different sepiolite samples. There was no evidence for carcinogenic potential of sepiolite from Vicalvaro, Spain, whereas a high tumor incidence was reported for sepiolite from Finland. The low biological activity of the sepiolite from Vicalvaro, compared to the Finnish sample, could be caused by low in vivo persistence or by the short length of the fibers, or both. In this study a further sepiolite sample, obtained as a commercial sample originating from China, was investigated. This sample contained a higher fraction of fibers longer than 5 microns, comparable to the Finnish sepiolite sample. The fraction of fibers with a length > 5 microns was 0.12 and 2.2% for the Vicalvaro and Chinese sepiolite, respectively. For the fiber fraction longer than 8 microns, the corresponding values were 0.0045 and 0.82%. The in vivo persistence of the sepiolite samples from China and Vicalvaro was analyzed after intratracheal instillation of 2 mg in female Wistar rats. Fiber retention in the lungs was analyzed by transmission electron microscopy at different sacrifice dates up to 12 months after application. For the Vicalvaro sepiolite, a splitting of fiber bundles was found during retention time in the lung. Therefore, no half-time of the fiber clearance could be calculated from the number of fibers. The decrease of the calculated retained fiber mass was faster for the Vicalvaro sepiolite (T1/2 = 89 days) compared to the Chinese sepiolite (T1/2 = 129 days). For 2 or 3 rats per group, at sacrifice date 12 months after i.p. injection, the lung was investigated by histopathology. The main difference between both treatment groups was a more pronounced fibrotic response in the Chinese sepiolite-treated rats compared to those treated with Vicalvaro sepiolite. It is concluded that both the higher fraction of long sepiolite fibers and the slower elimination rate of the fiber mass in the Chinese sample were important factors for the different biological reaction in comparison with Vicalvaro sepiolite.

Administration, Inhalation↗
PubMed1997

Expression of epidermal growth factor and transforming growth factor alpha during ulcer healing. Time sequence study.

BACKGROUND: Growth factors such as epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) have been shown to share common receptor (EGFR) and to accelerate ulcer healing due to stimulation of cell proliferation, but the time sequence of expression of EGF and TGF alpha during ulcer healing has not been investigated. In this study the rate of cell proliferation and the gastric secretion and gene expression of mRNA for EGF and TGF alpha were determined during ulcer healing. METHODS: Gastric ulcers were induced in 150 Wistar rats by serosal application of 100% acetic acid (ulcer area, 14 mm2). Some of these animals were also equipped with a gastric fistula for the assessment of gastric secretion during ulcer healing. The animals were killed 0, 2, 4, 6, or 8 days after ulcer induction, and the ulcer area was determined. The mucosal sections with gastric ulcer were immunostained for proliferating cell nuclear antigen (PCNA) and for immunoexpression of EGF, TGF alpha, and EGFR. The expression of mRNA EGF and mRNA TGF alpha was also determined in the ulcer margin by reverse transcriptase (RT) polymerase chain reaction (PCR) using specific primers. RESULTS: Two, 4, 6, and 8 days after ulcer induction the gastric ulcer area was gradually reduced from the initial size (day 0) by 47%, 70%, 80%, and 87%, respectively, and this was accompanied by an increase in PCNA with its maximum on day 4. The gastric acid and pepsin secretion was significantly reduced by 75% and 79%, respectively, on day 2 after ulcer induction but then the secretion tended to return to normal value by day 8. The expression of EGF, TGF alpha, and EGFR was negligible on day 0 but increased significantly during the healing, reaching maximum on day 4. Expression of EGF mRNA was detected on days 2, 4, and 6, and that of TGF alpha mRNA on days 2, 4, 6, and 8 after ulcer induction, with the most intense signals for both transcripts observed on day 2. CONCLUSIONS: 1) The enhancement in cell proliferation during ulcer healing may be mediated by increased release of EGF and TGF alpha; 2) the expression of EGF and TGF alpha mRNA precedes the overexpression of these growth factors at the ulcer margin during ulcer healing; and 3) the overexpression of growth factors coincides with the inhibition of gastric secretion and increased blood flow at the ulcer margin, indicating that these factors affect gastric secretion and blood flow in the course of ulcer healing.

Animals↗
PubMed1997

Melanosis coli--a harmless pigmentation or a precancerous condition?

UNLABELLED: Melanosis coli has long been considered as a harmless pigmentation of the colorectum associated with the use of laxatives containing anthraquinone. Recent experimental and clinical studies, however, have provided some evidence of a possible association between melanosis coli/laxative use and colorectal cancer. METHODS: In 2.229 consecutive patients we retrospectively analyzed the association of melanosis coli and laxative use with colorectal neoplasia. All the patients had undergone total colonoscopy, and the colorectal neoplasias had been examined histopathologically in accordance with the WHO classification. Information concerning laxative use, bowel habits and family history of colorectal cancer was obtained from the medical records. The statistical analysis was done using the Mantel-Haenszel-test for linear association. RESULTS: The presence of colorectal cancer was not associated with melanosis coli or laxative use. However, colorectal adenomas were found significantly more frequently in patients with melanosis coli than in those without melanosis (p = 0.0002). But adenomas associated with melanosis coli were significantly smaller than those not associated with melanosis (p < 0.0001), and were located predominantly in the proximal colon (p = 0.0002). In the patients with melanosis coli the relative risk was significantly higher for tubular (1.80; 95% CI: 1.26-2.56) and tubulovillous adenomas (2.03; 95% CI: 1.09-3.76), but not for villous adenomas. No significant differences were found in the grade of dysplasia of adenomas in patients with, and those without, melanosis coli. CONCLUSION: There appears to be no association between colorectal cancer and melanosis coli or laxative use. Colorectal adenomas are more frequently found in patients with melanosis coli. Colorectal adenomas do not contain the melanin-like pigmentation. The association of adenomas with melanosis coli can be explained by the ease of detection of even tiny polyps as white spots within a dark-colored colonic mucosa.

Adenoma↗
PubMed1997

[Morphological changes in human colon carcinoma after chemotherapy with 5-fluorouracil--a study in the nude mouse model].

Colorectal cancer represents one of the most important challenges in the field of cancer chemotherapy. 5-fluorouracil (5-FU) is used as the first-choice chemotherapeutic agent in the treatment of advanced gastrointestinal cancer. Despite this fact very little is known about the morphological changes of colon carcinoma after treatment with 5-FU. Thymusaplastic nude mice (n = 59) with subcutaneously heterotransplanted human coloncarcinoma (tubulo-papillary adenocarcinoma, grade II-III) were treated with 5-FU (40 mg/kg/body weight i. p. for five days). The animals were sacrificed, tumors were removed at 0 h, 24 h, 36 h, 48 h, 54 h, 60 h, 66 h, 72 h, 94 h, 118 h, 240 h after chemotherapy and the tumor tissue was embedded for light-microscopic and ultrastructural examination. Hydropic mitochondria and cytoplasmatic vacuoles were observed in tumor cells as early as 0 h after chemotherapy. These changes displayed a focal pattern. Damaged tumor tissue was surrounded by tumor cells with intact ultrastructure. In some regions tumor cells were separated from the basal membrane and showed signs of necrosis. These focal changes within the tumor tissue were observed from 0-240 h after treatment. Tumor capillaries did not show any damage. Treatment with 5-FU led to focal cytotoxic effects in the tumor. The remaining intact vascular system of the tumor may be a target for new therapy modalities.

Adenocarcinoma, Papillary↗
PubMed1996

Color doppler ultrasound of liver lesions: signal enhancement after intravenous injection of the ultrasound contrast agent Levovist.

Patients with focal liver lesions (hemangioma, focal nodular hyperplasia, adenoma, hepatocellular carcinoma, metastatic lesions, focal fatty lesion) received the ultrasound contrast agent Levovist (300 mg/mL and 400 mg/mL) intravenously. This ultrasound contrast agent (a suspension of micrometer-sized microparticles of galactose and microscopic gaseous bubbles) can pass through the lungs without impairment. After the administration of Levovist, increased color flow signals were detected in the liver. Five of 6 patients with metastatic liver lesions showed previously undetected blood flow in the rim of the tumor. In 4 patients with hepatocellular carcinoma, enhanced signal intensity was observed in the vessels of the rim and in 3 of those patients in the center of the tumor. One patient with adenoma and one patient with focal nodular hyperplasia showed signal enhancement in the central area of the tumor. No signal enhancement was observed in hemangiomas, a focal fatty lesion, or in a carcinoid metastatic lesion. Levovist increased the echointensity of normal and tumor vessels in liver lesions. This new ultrasound contrast agent led to the detection of tumor vessels previously not detectable by conventional color flow imaging.

Adenoma↗
PubMed1996

Absence of effect of caffeine on the thyroid in the Syrian golden hamster: results of a 90-day study.

Caffeine in drinking water was offered ad lib. to male and female Syrian golden hamsters (Mesocricetus auratus W) for 90 days. Animals were randomly assigned to three dose groups (91.3, 274 and 822 mg/litre) and one control group (filtered tap water), each consisting of 20 male and 20 female animals. In relation to body weight, mean caffeine consumption was higher in females (low dose: 14.7; medium dose: 50.8; high dose: 104.8 mg/kg body weight/day) than males (low dose: 9.0; medium dose: 24.6; high dose: 65.2 mg/kg body weight/day). Caffeine in plasma was measured after 3 days, 3 wk and 3 months of treatment. As expected from calculation of the caffeine intake, mean values were higher in females (low dose: 0.6; medium dose: 3.6; high dose: 7.2 mg/litre) than in males (low dose: 0.4; medium dose: 0.7; high dose: 2.9 mg/litre). After 3 days of treatment, a transient, non-dose-related increase in mean (SEM) tri-iodothyronine (n=10) was found in the medium and high-dose (751+/-23 and 742+/-25 ng/litre, respectively) groups of males compared with that in the controls (610+/-39 ng/litre)(P<0.05). The values measured at later time points (days 24 and 91) were similar in all groups. No treatment-related changes were found in thyroxine (days 3, 24 and 91) and other clinicochemical analytes (day 91), absolute and relative adrenal weight (day 91), gross pathology and thyroid histopathology (day 91). In conclusion, no signs of thyroid toxicity of caffeine were observed in the Syrian golden hamster.

Administration, Oral↗
PubMed1996

Laser-supported high-temperature MAS NMR for time-resolved in situ studies of reaction steps in heterogeneous catalysis.

The temperature of zeolite samples containing various adsorbed molecules was rapidly changed (within 15 s) from room temperature to 600 K by means of a laser beam. The location of the sealed glass ampoule in a boron nitride container decreases the temperature gradient in the sample and avoids laser-induced reactions. The technique facilitates time-dependent magic-angle-spinning (MAS) NMR spectroscopy of high-temperature reactions which take place within 60 s. The H-D exchange in the hydrogen form of zeolites loaded with fully deuterated molecules, the methanol-to-gasoline conversion and the catalytic ethylbenzene disproportionation in zeolites were monitored by 13C and 1H MAS NMR by means of a "stop and go" method.

Benzene Derivatives↗
PubMed1996

Regulated binding of PTP1B-like phosphatase to N-cadherin: control of cadherin-mediated adhesion by dephosphorylation of beta-catenin.

Cadherins are a family of cell-cell adhesion molecules which play a central role in controlling morphogenetic movements during development. Cadherin function is regulated by its association with the actin containing cytoskeleton, an association mediated by a complex of cytoplasmic proteins, the catenins: alpha, beta, and gamma. Phosphorylated tyrosine residues on beta-catenin are correlated with loss of cadherin function. Consistent with this, we find that only nontyrosine phosphorylated beta-catenin is associated with N-cadherin in E10 chick retina tissue. Moreover, we demonstrate that a PTP1B-like tyrosine phosphatase associates with N-cadherin and may function as a regulatory switch controlling cadherin function by dephosphorylating beta-catenin, thereby maintaining cells in an adhesion-competent state. The PTP1B-like phosphatase is itself tyrosine phosphorylated. Moreover, both direct binding experiments performed with phosphorylated and dephosphorylated molecules, and treatment of cells with tyrosine kinase inhibitors indicate that the interaction of the PTP1B-like phosphatase with N-cadherin depends on its tyrosine phosphorylation. Concomitant with the tyrosine kinase inhibitor-induced loss of the PTP1B-like phosphatase from its association with N-cadherin, phosphorylated tyrosine residues are retained on beta-catenin, the association of N-cadherin with the actin containing cytoskeleton is lost and N-cadherin-mediated cell adhesion is prevented. Tyrosine phosphatase inhibitors also result in the accumulation of phosphorylated tyrosine residues on beta-catenin, loss of the association of N-cadherin with the actin-containing cytoskeleton, and prevent N-cadherin mediated adhesion, presumably by directly blocking the function of the PTP1B-like phosphatase. We previously showed that the binding of two ligands to the cell surface N-acetylgalactosaminylphosphotransferase (GalNAcPTase), the monoclonal antibody 1B11 and a proteoglycan with a 250-kD core protein, results in the accumulation of phosphorylated tyrosine residues on beta-catenin, uncoupling of N-cadherin from its association with the actin containing cytoskeleton, and loss of N-cadherin function. We now report that binding of these ligands to the GalNAcPTase results in the absence of the PTP1B-like phosphatase from its association with N-cadherin as well as the loss of the tyrosine kinase and tyrosine phosphatase activities that otherwise co-precipitate with N-cadherin. Control antibodies and proteoglycans have no such effect. This effect is similar to that observed with tyrosine kinase inhibitors, suggesting that the GalNAcPTase/proteoglycan interaction inhibits a tyrosine kinase, thereby preventing the phosphorylation of the PTP1B-like phosphatase, and its association with N-cadherin. Taken together these data indicate that a PTP1B-like tyrosine phosphatase can regulate N-cadherin function through its ability to dephosphorylate beta-catenin and that the association of the phosphatase with N-cadherin is regulated via the interaction of the GalNAcPTase with its proteoglycan ligand. In this manner the GalNAcPTase-proteoglycan interaction may play a major role in morphogenetic cell and tissue interactions during development.

Actins↗
PubMed1996

Acceleration of wound healing in gastric ulcers by local injection of neutralising antibody to transforming growth factor beta 1.

BACKGROUND: Application of neutralising antibodies (NAs) to transforming growth factor beta 1 (TGF beta 1) improves wound healing in experimental glomerulonephritis and dermal incision wounds. TGF beta 1 has been detected in the stomach, but despite the fact that this cytokine plays a central part in wound healing no information is available to determine if modulation of the TGF beta 1 profile influences the healing of gastric ulcers. This study examines gastric ulcer healing in the rat after local injection of NAs to TGF beta 1. METHOD: Chronic gastric ulcers were induced in Wistar rats by the application of 100% acetic acid to the serosal surface of the stomach. Immediately after ulcer induction and on day 2, NAs to TGF beta 1 (50 micrograms), TGF beta 1 (50 ng), saline or control antibodies (IgG; 50 micrograms) were locally injected into the subserosa. Controls received no subserosal injections. Animals were killed on day 5 or 11, the ulcer area was measured planimetrically, sections were embedded in paraffin wax, and stained with trichrome or haematoxylin and eosin. Depth of residual ulcer was assessed on day 11 by a scale of 0-3, the percentage of connective tissue was determined by a semiquantitative matrix score and granulocytes and macrophages in the ulcer bed were also assessed. RESULTS: The application of NAs to TGF beta 1 led to a significant acceleration of gastric ulcer healing on day 11 (0.6 (SD 0.8) v 3.7 (SD 2.6) mm2), a reduction in macrophages (23.7 (SD 22.6) v 38 (26) per 40 x power field) and granulocytes (8.5 (SD 5.6) v 20 (10) per 40 x power field), fewer histological residual ulcers (mean 1 (SD 0.9) v 2 (1.1)), a reduced matrix score, and a regenerative healing pattern. Excessive scarring was seen in the TGF beta 1 treated group. CONCLUSION: Further treatment of gastric ulcers may induce a new treatment modality by local injection of NA to TGF beta 1 in an attempt to accelerate and improve ulcer healing.

Animals↗
PubMed1996

Expression of epidermal growth factor and transforming growth factor-alpha after exposure of rat gastric mucosa to stress.

BACKGROUND: This study was designed to determine whether transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and their common receptor (EGFR) are involved in the recovery of the gastric mucosa after exposure to water immersion and restraint stress. METHODS: Wistar rats were exposed to a standard period (3.5 h) of water immersion and restraint stress. Animals were killed immediately or 2 h, 4 h, 6 h, or 12 h after the stress. Tissues were removed, the area of the ulcerations was measured planimetrically, half of the stomach was taken for measurement of DNA synthesis, and the other half was embedded in paraffin. Sections were stained immunohistochemically for proliferating nuclear antigen (an index of cellular proliferation) and TGF-alpha, EGF, and EGFR. RESULTS: A single stress insult resulted in numerous haemorrhagic erosions in the oxyntic mucosa and a significant drop in DNA synthesis. During the recovery phase a marked increase in the expression of EGF peaked at 4 h, whereas the expression of EGFR peaked 6 h after stress. Thereafter the labelling indices for EGF and EGFR decreased, whereas DNA synthesis showed a gradual increase starting after about 6 h and peaking 12 h after the stress. In contrast, immunohistochemical expression of TGF-alpha showed a constant increase for up to 12 h after stress. Cell proliferation reached a maximum after 6 h and returned to normal values 12 h after the stress. CONCLUSIONS: EFG and TGF-alpha and their receptors are involved in the mucosal recovery from stress, and this is followed by enhanced DNA synthesis and mucosal cell proliferation.

Animals↗
PubMed1996

Mucosal irritation, adaptive cytoprotection, and adaptation to topical ammonia in the rat stomach.

BACKGROUND: The urease-ammonia (NH4OH) system has been proposed to play a major role in the pathogenesis of the Helicobacter pylori-associated gastritis, but the mechanism of the mucosal damage has not been fully explained. This study was designed to examine possible adaptive cytoprotection and the adaptation of rat gastric mucosa to the irritant action of NH4OH and urease. METHODS AND RESULTS: Single application of NH4OH alone in various concentrations (15-500 mM) caused concentration-dependent mucosal damage starting with 30 mM and reaching a maximum at 250 mM NH4OH, similar to that obtained with 100% ethanol; it was accompanied by a decrease in gastric blood flow (GBF) to approximately 30% of the normal value. When the mucosa was first exposed to the low, non-damaging concentration (15 mM) of NH4OH and then insulted with 100% ethanol, the extent of ethanol damage was greatly attenuated as compared with that caused by ethanol alone. This adaptive cytoprotection was accompanied by the rise in GBF and reversed, in part, by the pretreatment with indomethacin, an inhibitor of prostaglandin (PG)-cyclooxygenase; with L-NAME, a blocker of NO-synthase; or with capsaicin deactivating the sensory nerves. Damaging concentrations of NH4OH (125 mM) caused widespread mucosal damage after the first application, but with repeated insults with 125 mM NH4OH a gradual reduction in the mucosal lesions, accompanied by enhanced mucosal cell proliferation and over-expression of epidermal growth factor (EGF) (using immunocytochemistry) and mRNA of EGF (using trans-reverse polymerase chain reaction), were observed. CONCLUSIONS: NH4OH alone damages gastric mucosa only at the concentration exceeding that found in H. pylori-infected stomachs, whereas at lower concentrations it acts as 'mild' irritant to induce adaptive cytoprotection. This adaptive cytoprotection appears to be mediated, in part, by endogenous PG, sensory nerves, and an arginine-NO-dependent pathway, and repeated applications of NH4OH induce gastric adaptation, probably mediated by enhanced expression of EGF and its receptors and by an increased cell proliferation.

Adaptation, Physiological↗
PubMed1996

Salivary and gastric luminal release of epidermal growth factor under basal conditions and after pentagastrin stimulation in healthy subjects and in duodenal ulcer patients before and after eradication of Helicobacter pylori.

Epidermal growth factor (EGF) is secreted by salivary and Brunner's glands and shows a potent inhibitory effect on gastric acid and stimulatory influence on mucosal growth and protection but little is known about the effect of the Helicobacter pylori (Hp) infection on the release of EGF. In this study the salivary and gastric concentrations of EGF have been measured and gastric mucosal expression of EGF has been determined in 25 Hp positive duodenal ulcer (DU) patients before and after the eradication of Hp (using triple therapy with omeprazole, 20 mg bd, amoxycillin, 500 mg qd and metronidazole, 500 mg bd for 2 weeks) and in 10 healthy controls under basal conditions and following pentagastrin (2 micrograms/kg-h) stimulation. Basal salivary and gastric concentrations of EGF were similar and no significant difference was found between DU patients and healthy controls. Pentagastrin infusion (2 micrograms/kg-h) caused a significant increase in EGF release into saliva and gastric juice both in healthy controls and DU patients but in DU patients the Hp eradication resulted in several folds higher basal and pentagastrin-induced gastric EGF content than that before the anti-Hp therapy, whereas such Hp eradication had no significant influence on basal and pentagastrin-induced salivary EGF. Antral mucosal expression of EGF in Hp-positive DU patients was significantly higher than that in healthy Hp-negative controls and this elevation persisted after eradication of Hp. Basal and pentagastrin-induced gastric acid outputs in Hp-positive DU patients were significantly higher than in healthy controls and they were slightly reduced after the triple therapy. In all DU patients, 4 weeks after termination of anti-Hp therapy, a complete ulcer healing occurred. We conclude that (1) the stomach is capable of secreting large amounts of EGF and pentagastrin appears to be a potent stimulus of salivary and gastric EGF release; (2) the Hp infection reduces the release of gastric EGF and the eradication of Hp results in the augmentation of basal and pentagastrin-induced EGF release into the stomach but not into the saliva and (3) since the eradication of Hp infection in DU patients resulted in DU healing and this was accompanied by an increase in EGF release, we conclude that EGF plays a crucial role in the DU healing process.

Duodenal Ulcer↗
PubMed1996

Subserosal application of transforming growth factor-beta 1 in rats with chronic gastric ulcers: effect on gastric ulcer healing and blood flow.

Transforming growth factor beta 1 (TGF-beta 1) has been shown to play a central role in wound healing. This peptide has been detected in the stomach, but no information is available at present whether TGF-beta 1 influences the healing of gastric ulcers and whether the mucosal expression of TGF-beta 1 changes in the course of this healing. In this study, gastric ulcers were induced by serosal application of acetic acid and TGF-beta 1 or vehicle saline was injected twice into the subserosa around the ulcer area, once immediately after ulcer induction and two days later. Local application of TGF-beta 1 led to significant acceleration of gastric ulcer healing. Gastric blood flow at the ulcer margin was significantly higher than that in the ulcer crater but no significant difference was found in this flow between studied groups. Immunohistochemistry showed that the expression of TGF-beta 1 reached the peak at day 2 and then declined in the course of healing. We conclude that TGF-beta 1 accelerates ulcer healing possibly by increasing the formation of granulation tissue and cell migration probably mediated by locally expressed TGF-beta 1 but the healing effects of TGF-beta 1 do not depend on the vascular factor.

Animals↗
PubMed1995

207Pb NMR detection of spinning-induced temperature gradients in MAS rotors.

The position of the 207Pb MAS NMR resonance from Pb(NO3)2 at a given inlet temperature of the spinning air depends on the rotation frequency, the diameter and geometry of the rotor, the position of the sample in the rotor, and the bearing air pressure. Taking these effects into consideration, the use of Pb(NO3)2 as a chemical shift thermometer gives a temperature accuracy of (0.1 K for a very small sample and a MAS-induced temperature gradient of 4 K for a 4 mm sample spun at 10 kHz.

Lead↗