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Biomedical subjects

E G Hahn

Publications and source records attributed to E G Hahn.

At least 199 records · Page 11Linked to original sources

In vivo efficacy of heated and non-heated humidifiers during nasal continuous positive airway pressure (nCPAP)-therapy for obstructive sleep apnoea.

Upper airway dryness is a frequent side-effect of nasal continuous positive airway pressure therapy (nCPAP) in obstructive sleep apnoea (OSA). In this situation, heated or non-heated passover humidifiers are often added to the nCPAP-therapy. The efficacy of these two modes in terms of increasing the absolute humidity of the inspired air in vivo has so far not been established. The present investigation was therefore designed to compare various heated and non-heated passover humidifiers in terms of the their ability to increase the absolute humidity in the inspired air during nCPAP. In six healthy test individuals, nCPAP-therapy at pressures of 5 mbar and 10 mbar was simulated, and the relative humidity and temperature of the air within the tube at the junction between CPAP tube and mask were measured. In each test person, measurements were carried out both with and without the two heated (HC 100, Fischer&Paykel Inc., New Zealand and HumidAire, ResMed Ltd., Australia) and two non-heated (Oasis and Humidifier, both from Respironics Inc., U.S.A.) passover humidifiers under steady-state conditions. The absolute humidity was calculated from the relative humidity and temperature measurements. The mean (SD) absolute humidity (gm(-3)) in the steady-state was significantly (P<0.05 higher with each of the humidifiers than that calculated when no humidifier was used. The relevant figures were as follows: no humidifier: 10(-2) (1.8) gm(-3) (at 5 mbar)/9.8 (1.8) gm(-3) (at 10 mbar); Humidifier: 16.4 (0.97)/15.6 (1.26); Oasis: 17.3 (0.97)/ 16.7 (0.93); HC100: 26.5 (1.40)/26.2 (1.23); HumidAire: 31.8 (2.50)/30.9 (2.64). The mean increase in absolute humidity (in gm(-3)) with the aid of the heated humidifiers was 16.3 (5 mbar) gm(-3)/16.4 (10 mbar) gm(-3) with HC100 and 21.6/21.1 with HumidAire, and in both cases was clearly and significantly (P=0.028) higher in comparison with the non-heated humidifiers--6.2/5.8 with Humidifier and 7.2/6.9 with Oasis. In terms of the absolute humidity achieved within the CPAP tube system, the heated humidifiers were clearly superior to the non-heated humidifiers. These results were, however, obtained under laboratory conditions, and therefore cannot be translated unreservedly to the situation represented by long-term CPAP-treatment. Furthermore, it is possible that the smaller humidification capacity of the non-heated humidifiers may still suffice to meet the requirements of clinical use in terms of effectively preventing dry airways under CPAP treatment. This point, however, needs further investigation on the basis of long-term clinical studies.

Adult↗

[Ileocecal manifestation of Schoenlein-Henoch purpura as a rare differential Crohn disease diagnosis].

In the case of a 21-year-old patient gastroscopy and coloscopy were performed because of recurrent abdominal pain with diarrhea and vomiting. Colonoscopy showed moderate signs of inflammation of the rectum and aphthoid ulcerations in the terminal ileum. Since the macroscopic and clinical presentation was compatible with Crohn's disease, therapy with sulfasalacine was started. Because histology showed only lymphoid hyperplasia and the patient was asymptomatic at that time, the medication was ceased. Recurrence of abdominal pain and weight loss, proteinuria and a recurrent palpable purpura of the shanks in synopsis with the result of the previous colonoscopy led to a suspected diagnosis of Schoenlein-Henoch purpura with cutaneous, renal and abdominal manifestation which was confirmed by dermal and renal biopsies.

Adult↗

Analysis of the risk factors associated with endoscopic sphincterotomy techniques: preliminary results of a prospective study, with emphasis on the reduced risk of acute pancreatitis with low-dose anticoagulation treatment.

BACKGROUND AND STUDY AIMS: The aim of the present study was to analyze the risk factors associated with complications of endoscopic sphincterotomy (ES). PATIENTS AND METHODS: In all consecutive endoscopic sphincterotomies carried out between September 1994 and December 1996, the possible risk factors (12 patient-related factors and 12 procedure-related ones), as well as the concomitant medical treatment, indications, techniques, and success of endoscopic sphincterotomy were evaluated prospectively. Risk factors were analyzed on an exploratory basis using univariate methods. "Potential risk factors" (univariate, P<0.1) underwent multivariate analysis to determine independent "risk factors" (multivariate, P<0.05). In addition, the complication rate was calculated according to the number of potential risk factors present. RESULTS: A total of 438 patients who underwent ES were analyzed. Complications occurred in 7.5% (n = 33; acute pancreatitis 4.3%, hemorrhage 2.3 %, cholangitis 0.9%, technical 0.2%). Statistical analysis of the complications identified three independent risk factors (coagulopathy, patient age (< or =60 years, pancreas divisum), and one protective factor (pancreatic duct obstruction). The frequency of acute pancreatitis was increased by two independent risk factors (pancreas divisum, ES frequency <40 procedures/year) and was reduced if low-dose anticoagulation (unfractionated heparin or low molecular weight heparin) was administered (0.9%, one of 115 vs. 5.8%, 18 of 313; P<0.05). The effect of anticoagulation was not confounded by the presence or absence of other potential risk factors for acute pancreatitis. Neither the risk nor the severity of hemorrhage were increased by low-dose anticoagulation. Due to the low number of events, only potential risk factors for hemorrhage were identified (coagulopathy, intensive-care treatment). The overall complication rate and the incidence of pancreatitis and hemorrhage increased significantly depending on the number of simultaneous potential risk factors present (P<0.0001). CONCLUSIONS: Patients at risk for complications after endoscopic sphincterotomy can be identified by risk factor analysis. These data suggest the hypothesis that low-dose anticoagulation prior to endoscopic sphincterotomy reduces the risk of acute pancreatitis after sphincterotomy.

Acute Disease↗

[Hepatic Doppler perfusion index--a sensitive screening method for detecting liver metastases?].

UNLABELLED: The sonographic measurement of the Doppler perfusion index (DPI)--the ratio of blood flow in the hepatic artery to total liver blood flow--has been suggested to represent a method of detecting even small liver metastases. AIM: To evaluate the DPI measurement in our patients with liver metastases of colorectal cancer, gastric and bronchial carcinoma. METHOD: 36 patients with liver metastases were compared to 21 control subjects. The hepatic arterial and portal venous blood flows were calculated from the product of the average velocity of flow and the cross-sectional lumen of the vessel. Each measurement was performed three times by two independent examiners. RESULTS: Patients with metastases had a significantly higher hepatic blood flow and a significantly higher DPI (p = 0.0004; M +/- SD 0.23 +/- 0.11; r 0.06-0.52) compared with controls (M +/- SD 0.14 +/- 0.06, r. 0.05-0.26). No significant difference was seen in the portal vein blood flow. The DPI-values measured by the two examiners differed by 25.98% +/- 23.20. CONCLUSION: DPI values in patients with liver metastases differ from those in control subjects due to an increased hepatic arterial blood flow. No clear separation of the two groups was possible because DPI values overlapped. The inter observer agreement in DPI seems clinically acceptable.

Adult↗

Light-induced autofluorescence spectroscopy for tissue diagnosis of GI lesions.

BACKGROUND: The present article describes light-induced autofluorescence spectroscopy using violet-blue excitation light for endoscopic in vivo measurements in the upper GI tract. The spectra of normal mucosa, cancer, and dysplastic lesions of the esophagus and stomach are presented and compared. METHODS: Over 120 spectra were obtained in 11 patients of normal mucosa and malignant lesions in the esophagus and stomach during routine endoscopy. A special light source capable of delivering either white or violet-blue light was used for the excitation of tissue auto-fluorescence via the endoscope. Endogenous fluorescence spectra emitted by the tissue were collected with a fiberoptic probe and analyzed with a spectrograph. After spectrographic measurements biopsies were taken for definitive classification of histopathologic status. RESULTS: As compared with normal mucosa, (pre) cancerous lesions were associated with special changes in the emitted fluorescence spectra. The spectrographic records were influenced by the intensity of the illumination and on the position of the probe (distance and angle). CONCLUSION: Fluorescence spectroscopy with a slightly modified conventional light source might be useful for the endoscopic detection of dysplasia and early-stage carcinoma in the upper GI tract. Prospective trials need to determine the sensitivity and specificity of this new method.

Adenoma↗

Activation of genes for superoxide dismutase, interleukin-1beta, tumor necrosis factor-alpha, and intercellular adhesion molecule-1 during healing of ischemia-reperfusion-induced gastric injury.

BACKGROUND: Ischemia followed by reperfusion (I/R) induces gastric lesions, probably due to excessive formation of free radicals, but the role of the scavenger of these radicals, proinflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), in the healing of these lesions has not been extensively studied. It is also unknown whether expression of intercellular adhesion molecule-1 (ICAM-1), which mediates neutrophil-induced injury and neutrophil infiltration, is involved in the recovery from I/R lesions. METHODS: I/R lesions were induced in Wistar rats by applying a small clamp to the celiac artery for 30 min (ischemia phase), followed by the removal of the clamp for 60 min (reperfusion phase). The influence of I/R on gastric secretion was also tested in rats equipped with a gastric fistula (GF) without or with the exposure to a standard period of I/R. Two series of rats (A and B) were used to determine the effects of exogenous and endogenous superoxide dismutase SOD (series A) and allopurinol, a xanthine oxidase inhibitor (series B), on the mucosal recovery from the gastric lesions induced by I/R. The animals were killed immediately after the exposure to I/R (0 h) and at 3 h, 24 h, or 3, 5, or 10 days after this I/R, the area of gastric lesions being measured by planimetry, and the gastric blood flow (GBF) determined by the H2 gas clearance method. Blood was withdrawn for measurement of plasma IL-1beta and TNF-alpha levels with enzyme-linked immunosorbent assay, and plasma gastrin with radioimmunoassay. Biopsy samples of oxyntic mucosa were taken for the assessment of SOD, IL-1beta, TNF-alpha, and ICAM-1 mRNAs by reverse-transcription polymerase chain reaction and Southern blot. RESULTS: Exposure to I/R resulted in acute gastric erosions, with the maximal increase of the area of these lesions observed 3 h after the end of I/R. This effect was accompanied by a decrease in the GBF, a significant increase in blood free radicals and plasma gastrin increments, and almost complete suppression of gastric secretion. Starting 24 h after I/R, the gastric superficial lesions progressed into deeper ulcers that healed progressively within 10 days, and this was accompanied by gradual restoration of the gastric secretion and the GBF. Treatment with SOD and allopurinol accelerated significantly the healing of I/R erosions, and this effect was accompanied by a significant increase in the GBF and the attenuation of blood free radicals. At 0, 3, and 12 h after I/R a significant decrease in SOD mRNA was observed, whereas expression of TNF-alpha, IL-1beta, and ICAM-1 showed a progressive increase starting immediately after I/R, reaching a maximum on day 3. The plasma level of TNF-alpha and IL-1beta started to increase on day 3 and peaked on day 5 after I/R, being still significantly higher at day 10 than that measured in the vehicle-treated control gastric mucosa. On day 10 the gastric ulcers were almost completely healed, and a decrease in the expression for TNF-alpha, IL-1beta, and ICAM-1 mRNA and an increase in the expression of SOD mRNA were observed. CONCLUSIONS: 1) exposure to I/R produces gastric lesions mediated by the excessive formation of free radicals, resulting in suppression of both gastric microcirculation and secretory activity of the stomach; 2) SOD and allopurinol accelerate the healing of I/R lesions, probably due to suppression of oxygen free radicals and improvement of gastric microcirculation; and 3) the upregulation of SOD mRNA, with subsequent increase in the SOD production and local release of IL-1beta and TNF-alpha, may activate ICAM-1 expression and neutrophil infiltration, which appear to play an important role in the progression of I/R-induced acute gastric erosions into chronic ulcers.

Allopurinol↗

Secretion and tissue content of eosinophil cationic protein in Crohn's disease.

To define further the role of eosinophils in the pathogenesis of Crohn's disease, the secretion rate and tissue content of eosinophilic cationic protein (ECP) were measured in colorectal samples. Mucosal biopsies were obtained from 22 controls and 20 patients with Crohn's disease during colonoscopy. After measurement of the initial basal ECP, release samples were incubated using a mucosa oxygenation system. Spontaneous and antiimmunoglobulin E (anti-IgE)-induced secretions of ECP were measured at different time points. For detection of the remaining tissue, ECP amount samples were mechanically homogenized after the incubation period. ECP measurement was performed by radioimmunoassay. Spontaneous ECP secretion rates during the incubation period were similar in all patient groups, whereas the initial basal ECP secretion was significantly increased in tissue affected by Crohn's disease. After stimulation with anti-IgE, ECP secretion was increased two-fold in controls and three-fold in patients with Crohn's disease. In tissue affected by Crohn's disease, ECP levels were found to be significantly increased in most segments of the lower gastrointestinal tract with the highest ECP concentrations in affected mucosa. This functional study demonstrates an enhanced immunologically mediated ECP secretion and an accumulation of ECP in the intestinal mucosa of Crohn's disease, indicating a local upregulation of eosinophils.

Adult↗

Helicobacter pylori infection delays healing of ischaemia-reperfusion induced gastric ulcerations: new animal model for studying pathogenesis and therapy of H. pylori infection.

OBJECTIVE: Helicobacter pylori (Hp) infection is a major risk factor of peptic ulcerations but studies on its pathogenicity are limited due to the lack of an adequate animal model. In this study we developed the new model of gastric Hp infection in rat gastric mucosa, with acute gastric erosions progressing into ulcers in animals subjected initially to ischaemia-reperfusion (I/R). DESIGN: I/R lesions were produced in rats by clamping the coeliac artery for 0.5 h followed by 1 h reperfusion and gastric inoculation with type I Hp strain (CagA and VacA positive) or type II Hp strain (CagA and VacA negative), obtained from fresh clinical isolates, or with vehicle (saline). Gastric secretion during recovery from I/R lesions was determined in a separate group of rats equipped with chronic gastric fistula to inoculate the animals with Hp and then to collect gastric juice for determination of gastric acidity and pepsin outputs as well as luminal content of somatostatin. METHODS: The animals were killed at 0, 3, 12 or 24 h and 3, 5, 10 or 15 days after Hp inoculation and the area of gastric lesions was determined planimetrically and gastric blood flow (GBF) was measured by the H2-gas clearance technique. The venous blood was withdrawn for measurement of plasma interleukin (IL)-1beta and tumour necrosis factor alpha (TNFalpha) by ELISA and plasma gastrin, luminal somatostatin by RIA and the mucosal expression of transforming growth factor (TGFalpha) was analysed using RT-PCR with specific primers. Gastric Hp infection was assessed by histology, rapid urease test and Hp culture. The effect of triple therapy with omeprazole, amoxycillin and tinidazole on Hp infection and ulcer healing was also determined. RESULTS: Ischaemia alone resulted in an immediate fall in GBF and almost complete suppression of gastric secretion but without any gastric lesions. When ischaemia was followed by 1 h of reperfusion, acute gastric erosive lesions immediately occurred, reaching a maximum at 12 h after I/R and progressing after 3 days to deeper gastric ulcers that disappeared after 15 days. In Hp-inoculated rats, the number of viable Hp colonies gradually increased, reaching maximum at day 10 with infection with type I and at day 15 with infection with type II Hp. At day 15 the difference in Hp colonization was not significantly different between the stomachs infected by type I and type II Hp. Inoculation, especially with the type I Hp strain, significantly delayed healing of I/R-induced acute lesions and accelerated their progression into deeper chronic ulcers. This effect was accompanied by a significant fall in GBF and a higher increment in plasma IL-1beta and TNFalpha levels. Gastric acid secretion, which was completely inhibited up to 12 h after I/R, returned to the control value 24 h upon completion of the I/R procedure. This return was delayed in Hp-infected rats and accompanied by a significant elevation of plasma gastrin and a decrease in luminal somatostatin. The immunoreactivity of TGFalpha and expression of TGFalpha mRNA determined by RT-PCR were well defined in intact gastric mucosa but were significantly decreased, especially in mucosa infected with type I Hp strain, at day 15 after I/R. The triple therapy which cured Hp infection completely abolished the delay in ulcer healing caused by Hp. CONCLUSIONS: (1) Gastric infection with the Hp strain expressing cagA and vacA encoded cytotoxins delays healing of I/R-induced acute gastric lesions due to an impairment of gastric microcirculation, and excessive proinflammatory cytokine release and suppression of anti-ulcer TGFalpha expression. (2) The I/R induced suppression of gastric acid secretion may contribute to the hypergastrinaemia as a secondary phenomenon and may account for the spread of Hp infection observed during the progression of acute erosions into chronic ulcers. (3) I/R induced gastric ulcers may be a useful model for studying the action of Hp infection on gastric ulcerogenesis in ischaemic stomach and for testing anti-Hp therapy.

Animals↗

Is endoscopic drainage of common bile duct stenoses in chronic pancreatitis up-to-date?

OBJECTIVE: Common bile duct (CBD) stenoses often complicate chronic pancreatitis (CP). Although endoscopic drainage is employed as a standard procedure in malignant CBD stenoses, it is not yet the approved standard therapy of CBD stenosis in CP. METHODS: The records of 31 patients with CBD stenosis in CP who had undergone endoscopic placement of plastic endoprostheses into the bile duct between January 1991 and February 1997 were analyzed retrospectively. In all, 18 patients suffered from jaundice and 13 patients exclusively showed serological cholestasis. Upstream dilation of the CBD (19 +/- 6.6 mm, 12-35 mm) was detected by ERCP in all patients. In total, 101 endoprostheses were implanted endoscopically, exchanged after 3 +/- 2 months, and removed after 10 +/- 8 months. RESULTS: All jaundiced patients showed immediate improvement of cholestasis after drainage. At the time of last exchange or after stent removal, prestenotic CBD dilation was reduced in 55% of all patients. Complete regression of stenosis and prestenotic dilation was accomplished only in 13%; dilation remained unchanged in 10%, and even showed progression in 22%. A total of 29 patients were followed-up over 24 months. Cholestatic parameters remained normal in all patients with complete normalization of the CBD, and were only moderately increased in another 10 patients, 7 and 28 months after stent removal, respectively. CONCLUSIONS: Technical and immediate clinical success of CBD stenting in patients with CBD stenoses due to CP is high; however, long-term complete normalization of the bile duct is rare. Endoscopic drainage of CBD-stenosis in patients with CP can be recommended to alleviate acute cholestasis, but not yet as a definite treatment.

Acute Disease↗

Anthranoid laxative use is not a risk factor for colorectal neoplasia: results of a prospective case control study.

BACKGROUND: Anthranoid laxatives are the most commonly used purgatives in the therapy of acute and chronic constipation. Recent experimental data and a prospective cohort study provide evidence of a possible risk of anthranoid use for the development of colorectal neoplasms. MATERIALS AND METHODS: We performed a prospective case control study at the University of Erlangen to investigate the risk of anthranoid laxative use for the development of colorectal adenomas or carcinomas. A total of 202 patients with newly diagnosed colorectal carcinomas, 114 patients with adenomatous polyps, and 238 patients (controls) with no colorectal neoplasms who had been referred for total colonoscopy were studied. The use of anthranoid preparations was assessed by standardised interview, and endoscopically visible or microscopic melanosis coli was studied by histopathological examination. RESULTS: There was no statistically significant risk of anthranoid use for the development of colorectal adenomas (unadjusted odds ratio 1.0; 95% CI 0.5-1.9) or carcinomas (unadjusted odds ratio 1.0; 95% CI 0.6-1.8). Even after adjustment for the risk factors age, sex, and blood in the stools by logistic regression analysis the odds ratio for adenomas was 0.84 (95% CI 0. 4-1.7) and for carcinomas 0.93 (95% CI 0.5-1.7). Also, there were no differences between the patient and control groups for duration of intake. Macroscopic and high grade microscopic melanosis coli were not significant risk factors for the development of adenomas or carcinomas. CONCLUSION: Neither anthranoid laxative use, even in the long term, nor macroscopic or marked microscopic melanosis coli were associated with any significant risk for the development of colorectal adenoma or carcinoma.

Adenoma↗

Protective action of lipopolysaccharidesin rat caerulein-induced pancreatitis: role of nitric oxide.

Lipopolysaccharides (LPS), the component of the cell wall of gram-negative bacteria, have been implicated in the pathogenesis of acute pancreatitis, but the mechanism of their action on the pancreas has not been fully explored. The aim of this study was to investigate the effects of various doses of LPS on the integrity of intact pancreas and that involved in acute caerulein-induced pancreatitis (CIP) in the rat and to compare these effects with those of nitric oxide (NO) donor, S-nitrose-acetylpenicillamine (SNAP). The expression of constitutive NO synthase (cNOS) and inducible NO synthase (iNOS) mRNA was also examined in the isolated pancreatic acini obtained from the inflamed pancreas of rats treated with LPS. CIP was produced by subcutaneous (s.c.) infusion of caerulein (5 microg/kg.h for 5 h) to conscious rats. Bolus injections of various doses of LPS (0.1, 1, 10, 20 or 40 mg/kg) or SNAP (1.5, 3 or 6 mg/kg) were made intraperitoneally (i.p.) either alone or 30 min prior to s.c. infusion of caerulein to induce CIP. Infusion of caerulein produced acute pancreatitis confirmed by histological examination and manifested by an increase of pancreatic mass (by about 200%). Blood levels of amylase and lipase were augmented by 400 and 800% respectively, whereas the pancreatic blood flow (PBF) was decreased by 50% in rats with CIP. Injection of low doses of LPS (0.1-1 mg/kg i.p.) or SNAP (1.5-3 mg/kg i.p.) 30 min prior to caerulein infusion reversed the harmful effects of pancreatic overstimulation with caerulein and reduced significantly the histological manifestations of CIP such as edema, neutrophil infiltration and vacuolization of the acinar cells. These protective effects of low doses of LPS pretreatment on the pancreas were completely antagonized by the suppression of the activity of NO synthase (NOS) with N(G)-nitro-L-arginine (L-NNA) applied (20 mg/kg i.p.) 15 min prior to the LPS injection. Combination of L-arginine (100 mg/kg i.p.), a substrate for NOS, with L-NNA given prior to low doses of LPS, restored the LPS-induced protection of the pancreas in rats with CIP. In contrast, higher doses of LPS (20-40 mg/kg i.p.) or SNAP (6 mg/kg i.p.), which produced a significant fall of the PBF, did not protect the pancreas against CIP. Administration of various doses of LPS to rats with CIP resulted in significant and dose-dependent stimulation of NO biosynthesis in the isolated acini obtained from the pancreas of these animals. LPS enhanced the expression of both cNOS and iNOS in the pancreatic acini obtained from rats subjected to CIP. The signal for cNOS mRNA was detected in all samples, reaching peak at the protective dose of LPS (1 mg/kg i. p.), while iNOS was overexpressed only at the highest doses of LPS that failed to exhibit the protective activity. We conclude that the pretreatment with low doses of LPS protects the pancreas against the damage provoked by CIP and this effect could be attributed, at least in part, to the activation of L-arginine-NO system in the pancreas.

Animals↗

Water extracts of Helicobacter pylori suppress the expression of histidine decarboxylase and reduce histamine content in the rat gastric mucosa.

BACKGROUND: Acute Helicobacter pylori (Hp) infection in humans may be associated with markedly reduced gastric acid secretion, but the mechanism of this hypochlorhydria has not been fully explained. AIMS: This study was designed to investigate how water extracts (WE) of Hp applied on rat gastric mucosa affect gastric secretion and mucosal histamine concentration as well as the gene expression for histamine decarboxylase (HDC), the key enzyme converting histidine to histamine and for interleukin-1beta (IL-1beta), the important proinflammatory cytokine. MATERIALS AND METHODS: Wistar rats were surgically equipped with small cannulas to form gastric fistulas (GF). Four weeks after formation of GF, rats received either saline (control group) or WE obtained from type I Hp strain expressing CagA/VacA proteins and from type II Hp strain negative for CagA/VacA. Hp-WE was applied intragastrically (i.g.) in a volume of 1 ml at days 0, 2, 4 and 6 (total 4 times). At days 7 and 14, the secretory tests were performed during which basal gastric acid and pepsin secretion was examined and acid and pepsin outputs were measured. After secretory tests, the rats were sacrificed, the stomachs removed and the damage to the gastric mucosa was assessed by measuring the lesion area planimetrically and by histology, the gene expression in gastric mucosa for HDC and interleukin-1beta (IL-1beta) was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot. Additionally, somatostatin concentration in gastric juice, gastric mucosal histamine content and plasma gastrin and IL-1beta levels were determined using radioimmunoassay (RIA). RESULTS: Administration of Hp-WE failed to induce gross mucosal damage but microscopic examination revealed partial denudation of gastric surface epithelium without causing deep necrosis. In secretory tests, Hp-WE produced marked hypochlorhydria but type I Hp-WE induced significantly stronger inhibition of acid and pepsin secretion than type II Hp-WE, both at days 7 and 14. Both, type I and type II Hp-WE suppressed significantly the gene expression for HDC mRNA and lowered significantly gastric mucosal histamine content as compared to respective values in vehicle-treated control gastric mucosa. Furthermore, Hp-WE, resulted in a significant increase in expression of IL-1beta mRNA and a significant fall in luminal somatostatin concentration as well as a insignificant elevation of plasma gastrin level, the type I Hp-WE being more effective in these alterations than type II Hp-WE. CONCLUSIONS: (1) Ability of Hp-WE to induce superficial damage, the reduction in HDC mRNA and accompanying fall in gastric histamine release, contribute, at least in part, to marked hypochlorhydria observed in the stomach exposed to repeated Hp-WE treatments, and (2) the deleterious effect of Hp-WE on the gastric mucosa involves an impairment of gastrin-somatostatin link possibly resulting from the action of Hp-derived toxins and the induction in mucosal cells of proinflammatory cytokine such as IL-1beta.

Animals↗

Central leptin and cholecystokinin in gastroprotection against ethanol-induced damage.

BACKGROUND: Leptin, a product of the ob gene controlling food intake, has recently been detected in the stomach and shown to be released by cholecystokinin (CCK) and to induce gastroprotection against various noxious agents, but it is not known whether centrally applied leptin influences gastric secretion and mucosal integrity. AIMS: In this study we compared the effects of leptin and CCK-8 applied intracerebroventricularly (i.c.v.) on gastric secretion and gastric mucosal lesions induced by topical application of 75% ethanol. METHODS: Several major series of Wistar rats were used in this study. The effects of leptin or CCK applied i.c.v. on gastric secretion were examined using conscious rats with gastric fistulas. For the studies on gastroprotection the following series of rats were used to determine the effects of: (A) leptin and CCK applied centrally on this protection and the blockade of CCK(A) with loxiglumide (30 mg/kg i.p.) and CCK(B) receptors with RPR 102681 (30 mg/kg i.p.); (B) cutting of vagal nerves; (C) inactivation of sensory nerves by capsaicin (125 mg/kg s.c.); (D) inhibition of calcitonin gene-related peptide (CGRP) receptors with CGRP(8-37) (100 microg/kg i.p.), and (E) suppression of nitric oxide synthase (NOS) with N(G)-nitro-L-arginine methyl ester (L-NAME) (5 mg/kg i.v. ) on ethanol-induced gastric lesions in rats with or without the i.c.v. pretreatment with leptin or CCK-8. Rats were anesthetized 1 h after ethanol administration to measure the gastric blood flow (GBF) and then to determine the area of gastric lesions by planimetry. Blood was withdrawn for the measurement of plasma leptin and gastrin levels by radioimmunoassay and gastric biopsy samples were collected for the determination of cNOS and iNOS mRNA by RT-PCR. RESULTS: Leptin and CCK-8 (0.01-5 microg/kg i.c.v.) dose dependently attenuated gastric lesions induced by 75% ethanol; the doses reducing these lesions by 50% (ED(50)) were 0.8 and 1.2 microg/kg, respectively. The protective effects of leptin and CCK-8 applied i.c. v. were accompanied by a significant rise in plasma leptin level and an increase in GBF. Blockade of CCK(A) receptors with loxiglumide abolished the protective and hyperemic effects of CCK but not those of leptin, while RPR 10268, a specific antagonist of CCK(B) receptors, counteracted leptin-induced protection and the rise in the GBF but failed to influence those afforded by CCK-8. For comparison, pretreatment with peripheral CCK-8 or leptin (10 microg/kg i.p.) causing a similar rise in the plasma leptin level also significantly reduced gastric lesions induced by 75% ethanol. The protective and hyperemic effects of centrally administered leptin were abolished by vagotomy, producing a fall in plasma leptin levels, and significantly attenuated by sensory denervation with capsaicin, by pretreatment with the CGRP antagonist, CGRP(8-37), or with L-NAME. A strong signal for iNOS mRNA was recorded in the gastric mucosa of leptin- and CCK-8-treated animals, whereas cNOS mRNA was unaffected. CONCLUSIONS: (1) Central leptin exerts a potent gastroprotective action at a dose that has no influence on gastric secretion; (2) this protection depends upon CCK(B) receptors, vagal activity and sensory nerves, and involves hyperemia probably mediated by NO, and (3) leptin mimics the gastroprotective effect of CCK and may be implicated in the protective and hyperemic actions of this peptide on the rat stomach.

Animals↗

An auto-continuous positive airway pressure device controlled exclusively by the forced oscillation technique.

The forced oscillation technique (FOT) has been demonstrated to be a very sensitive tool for the assessment of upper airway obstruction during nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA). The present study was designed to evaluate the therapeutic efficacy of a novel auto-CPAP device based exclusively on the FOT. Following manual CPAP titration, 18 patients with OSA (mean apnoea/hypopnoea index (AHI) 48.0+/-28.1) were allocated to conventional CPAP and auto-CPAP treatment under polysomnographic control in randomized order. The patients were asked to assess their subjective daytime sleepiness using the Epworth Sleepiness Scale (ESS). The mean AHI during auto-CPAP treatment was 3.4+/-3.4 and was comparable with that obtained during conventional CPAP treatment (4.2+/-3.6). The analysis of sleep architecture, the arousal index (6.6+/-2.1 versus 7.3+/-4.4) or the ESS (5.6+/-1.8 versus 7.3+/-4.4) did not reveal any significant differences. However, the mean CPAP pressure during auto-CPAP treatment (0.84+/-0.26 kPa) and in particular the pressure applied in the lateral body position (0.74+/-0.35 kPa), was significantly lower than that employed in conventional CPAP treatment (0.93+/-0.16 kPa, both comparisons: p<0.05). The auto-continuous positive airway pressure device proved equally as effective as conventional continuous positive airway pressure. However, the mean treatment pressure was significantly reduced, especially when patients were sleeping in the lateral position.

Adult↗

Incidence and costs of adverse drug reactions during hospitalisation: computerised monitoring versus stimulated spontaneous reporting.

OBJECTIVE: To implement a computer-based adverse drug reaction monitoring system and compare its results with those of stimulated spontaneous reporting, and to assess the excess lengths of stay and costs of patients with verified adverse drug reactions. DESIGN: A prospective cohort study was used to assess the efficacy of computer-based monitoring, and case-matching was used to assess excess length of stay and costs. SETTING: This was a study of all patients admitted to a medical ward of a university hospital in Germany between June and December 1997. PATIENTS AND PARTICIPANTS: 379 patients were included, most of whom had infectious, gastrointestinal or liver diseases, or sleep apnoea syndrome. Patients admitted because of adverse drug reactions were excluded. METHODS: All automatically generated laboratory signals and reports were evaluated by a team consisting of a clinical pharmacologist, a clinician and a pharmacist for their likelihood of being an adverse drug reaction. They were classified by severity and causality. For verified adverse drug reactions, control patients with similar primary diagnosis, age, gender and time of admission but without adverse drug reactions were matched to the cases in order to assess the excess length of hospitalisation caused by an adverse drug reaction. RESULTS: Adverse drug reactions were detected in 12% of patients by the computer-based monitoring system and stimulated spontaneous reporting together (46 adverse reactions in 45 patients) during 1718 treatment days. Computer-based monitoring identified adverse drug reactions in 34 cases, and stimulated spontaneous reporting in 17 cases. Only 5 adverse drug reactions were detected by both methods. The relative sensitivity of computer-based monitoring was 74% (relative specificity 75%), and that of stimulated spontaneous reporting was 37% (relative specificity 98%). All 3 serious adverse drug reactions were detected by computer-based monitoring, but only 2 out of the 3 were detected by stimulated spontaneous reporting. The percentage of automatically generated laboratory signals associated with an adverse drug reaction (positive predictive value) was 13%. The mean excess length of stay was 3.5 days per adverse drug reaction. 48% of adverse reactions were predictable and detected solely by computer-based monitoring. Therefore, the potential for savings on this ward from the introduction of computer-based monitoring can be calculated as EUR56 200/year ($US59 600/year) [ 1999 values]. CONCLUSION: Computer monitoring is an effective method for improving the detection of adverse drug reactions in inpatients. The excess length of stay and costs caused by adverse drug reactions are substantial and might be considerably reduced by earlier detection.

Adverse Drug Reaction Reporting Systems↗