Glucocorticoids downregulate gene expression of GM-CSF, NAP-1/IL-8, and IL-6, but not of M-CSF in human fibroblasts

Cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage-CSF (M-CSF), neutrophil-activating peptide-1/interleukin-8 (NAP-1/IL-8), and interleukin-6 (IL-6) are pivotal in the regulation of hematopoiesis and immune responses. In mesenchymal cells, their expression is induced by tumor necrosis factor alpha (TNF) and other agents. We now show that, while induction of cytokine expression by TNF in human lung fibroblasts was parallel, glucocorticoid hormones differentially affected their production. Dexamethasone (1 mumol/L) concordantly repressed expression of GM-CSF, NAP-1/IL-8 and IL-6. RNA and protein levels were reduced to approximately 5%, 20%, and 30% of control cells, respectively, as determined by Northern blot analyses and immunoassays. A 50% reduction of RNA levels for all three cytokines occurred in the range of 1 hour. In contrast, dexamethasone (1 mumol/L) did not decrease M-CSF RNA levels and protein release. M-CSF RNA and protein levels were maintained even when dexamethasone (1 mumol/L) was present for the whole duration of a 48-hour TNF stimulation. Further experiments showed that dexamethasone downregulates expression of GM-CSF, NAP-1/IL-8, and IL-6 mainly by decreasing the mRNA stability of these cytokines, and that the dexamethasone-mediated repression of cytokine expression depends on ongoing protein and RNA syntheses. Our study suggests that glucocorticoid hormones repress expression of a set of cytokine genes important in conditions of stress. However, they seem not to affect M-CSF expression, which is likely to be more crucial in maintaining long-term functions of myeloid cells.

[Combined oral and endoscopic mepacrine therapy in therapy-resistant symptomatic giardiasis]

A case of extremely refractory infection with Giardia lamblia is described. A 28-year-old male patient with a 7-year history of mushy diarrhea and epigastric pain was repeatedly treated orally and intravenously, without success, with metronidazole, tinidazole, ornidazole, and mepacrine. The rate of success for these drugs is generally more than 90%. Only therapy with mepacrine orally in combination with intraduodenal administration, was successful. Therapeutic failure of 5-nitroimidazole derivatives is described in relation to immune deficiency syndromes and IgA deficit. None of these defects were found in this case.

Nucleotide sequence of the hemolysin I gene from Actinobacillus pleuropneumoniae

The DNA sequence of the gene encoding the structural protein of hemolysin I (HlyI) of Actinobacillus pleuropneumoniae serotype 1 strain 4074 was analyzed. The nucleotide sequence shows a 3,072-bp reading frame encoding a protein of 1,023 amino acids with a calculated molecular size of 110.1 kDa. This corresponds to the HlyI protein, which has an apparent molecular size on sodium dodecyl sulfate gels of 105 kDa. The structure of the protein derived from the DNA sequence shows three hydrophobic regions in the N-terminal part of the protein, 13 glycine-rich domains in the second half of the protein, and a hydrophilic C-terminal area, all of which are typical of the cytotoxins of the RTX (repeats in the structural toxin) toxin family. The derived amino acid sequence of HlyI shows 42% homology with the hemolysin of A. pleuropneumoniae serotype 5, 41% homology with the leukotoxin of Pasteurella haemolytica, and 56% homology with the Escherichia coli alpha-hemolysin. The 13 glycine-rich repeats and three hydrophobic areas of the HlyI sequence show more similarity to the E. coli alpha-hemolysin than to either the A. pleuropneumoniae serotype 5 hemolysin or the leukotoxin (while the last two are more similar to each other). Two types of RTX hemolysins therefore seem to be present in A. pleuropneumoniae, one (HlyI) resembling the alpha-hemolysin and a second more closely related to the leukotoxin. Ca(2+)-binding experiments using HlyI and recombinant A. pleuropneumoniae prohemolysin (HlyIA) that was produced in E. coli shows that HlyI binds 45Ca2+, probably because of the 13 glycine-rich repeated domains. Activation of the prohemolysin is not required for Ca2+ binding.

[Collagen colitis--a clinical entity of relevance]

Collagenous colitis is a clinical and pathological entity characterized by chronic watery diarrhea and deposition of collagen beneath the surface epithelium of the large intestine. By colonoscopy and barium enema the colon appears normal. The laboratory tests give usually normal results. 75% of the patients are middle-aged women with a mean age around 50 years. The etiology of the disease is still unknown. An association with various autoimmune diseases has been suggested, but was never proven. Up to now, it is not clear whether the collagenous colitis is a distinct entity or only an epi-phenomenon of another disease which leads to thickening of the collagen layer. Collagenous colitis is diagnosed if all other diseases with chronic watery diarrhea are excluded. A specific treatment is not known. Symptomatic treatment with bulk and antidiarrheal drugs improves the symptoms of most of the patients.

Pharmacokinetics and pharmacodynamics of a new transdermal delivery system for bopindolol

1. In two separate studies, each with 12 healthy male volunteers, the pharmacokinetic and dynamic properties of a transdermal delivery system for bopindolol were evaluated. 2. In study I it was shown that bopindolol absorption from a 14 mg patch occurred over the whole 7-day application period. No signs of a significant skin depot were found. 3. In study II, a linear pharmacokinetic behaviour but a non-linear kinetic/dynamic relationship was established for the patches over a dose range from 7 to 21 mg. Comparable peak effects of reduction in exercise-induced tachycardia were observed after different patch doses and an i.v. injection. However, the effect was significantly prolonged with the patches compared with the injection and was maintained over 7 days. 4. The patches showed a good local and systemic tolerability in both studies over a dosing interval of up to 7 days.

Flumazenil in the treatment of portal systemic encephalopathy--an overview

Hepatic encephalopathy is a complex neuropsychiatric syndrome associated with acute, subacute and chronic liver failure, involving increased neural inhibition by activation of the GABA/benzodiazepine inhibitory neurotransmitter system. Improvement by GABA and benzodiazepine receptor antagonists as well as by chloride ionophore blockers has been shown in animal experiments. Recent reports indicate that flumazenil may improve hepatic encephalopathy in man. To date 46 episodes of HE in 41 patients have been treated with flumazenil with a short term success rate of 72%. Most of the patients were screened for exogenous benzodiazepines and found negative. These interesting observations should now be investigated in a randomised double-blind controlled study in patients with HE to evaluate the efficiency of this therapy.

Effect of loxiglumide, a cholecystokinin antagonist, on pancreatic polypeptide release in humans

The purpose of this study was to determine the role of cholecystokinin in the regulation of postprandial pancreatic polypeptide secretion in humans. The pancreatic polypeptide responses to modified sham feeding and gastric instillation of a test meal were first compared with the response to oral ingestion of the same meal. The experiments were repeated under cholinergic (atropine) and cholecystokinin (loxiglumide) blockade. Atropine completely abolished the pancreatic polypeptide response to sham feeding and caused significant reductions after gastric and oral food intake. Loxiglumide, on the other hand, significantly reduced pancreatic polypeptide release to oral food (51% inhibition) without affecting the response to sham feeding. In separate experiments using a duodenal perfusion system, the effects of atropine and loxiglumide on intestinal phase-stimulated pancreatic polypeptide release were examined, and both cholinergic and cholecystokinin blockade induced complete suppression. It was concluded (a) that cholecystokinin is involved in postprandial pancreatic polypeptide response, especially during the intestinal phase stimulation, and (b) that the cholinergic system is crucial and superimposed on cholecystokinin in stimulating pancreatic polypeptide release.

A myeloperoxidase cDNA clone identifies an EcoRV RFLP

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[Diarrhea in returning travellers (etiology, diagnosis and therapy)]

International tourism is constantly expanding and traveller's diarrhea has become a common disease. Although traveller's diarrhea may already have ceased after return, more and more general practitioners are confronted with patients complaining of GUT-symptoms associated with the journey. To manage these patients the precise knowledge of the etiology of traveller's diarrhea and the forms leading to chronic diarrhea is mandatory. This review deals with the etiology of diarrhea after returning home from tropical/subtropical areas and gives special emphasis on adequate diagnosis and treatment. It also points to the importance of parasites as cause of chronic traveller's diarrhea. Parasitic disease needs more often antibiotic treatment than infectious diarrhea due to bacterial agents. We summarize the etiology, the diagnostic and therapeutic approach.

[Intramural hematoma of the duodenum as complication in anticoagulant therapy. Diagnosis and therapy]

We report the history of a 68-year-old man who has been hospitalized for an aortic valve endocarditis. The patient was under full anticoagulation therapy because of an artificial aortic valve (Omnicarbon 23 mm). During hospitalization the patient developed a subacute abdomen accompanied by upper gastrointestinal tract hemorrhage. At endoscopy and radiology an intramural hematoma of the duodenum was found. The typical findings of intramural hematoma such as abdominal X-ray, ultrasound, CT scan, selective small bowel transit and endoscopy are presented and the history as well as therapeutic modalities discussed.

[ERCP in bile duct dilatation with jaundice due to spontaneous hydatid cyst rupture. Diagnosis, differential diagnosis, therapy and result]

We report the case of a 17 years old Turkish patient hospitalized for colics and jaundice. Ultrasound, computer tomography and ERC showed enlarged intra- and extrahepatic bile ducts. The further investigations documented the rupture of a hepatic hydatid cyst into the biliary tract with obstructive jaundice. Other causes of jaundice as cystic duct malformation, calculi, tumours could be ruled out by surgery and histology. Etiology, diagnosis and treatment of hydatid jaundice are discussed.