Epidemiological trends of functional gastrointestinal disorders

Functional gastrointestinal disorders are highly prevalent in the population and in primary and secondary care centers. Most likely they have been highly prevalent for centuries but in the past the lack of appropriate diagnostic measures did not enable the precise exclusion of structural causes of symptoms. In recent decades the prevalence rates of Helicobacter pylori has clearly decreased. As a result the incidence of H. pylori-related structural diseases in the upper gut decreased. Thus the relative proportion of functional gastrointestinal disorders has increased and may result in the overall impression that the prevalence of functional gastrointestinal disorders has increased. Thus, the available data do not provide evidence that the prevalence of these disorders has changed in recent decades.

Depolarization of the liver cell membrane by metformin

Metformin (1,1-dimethylbiguanide; MET) is used in the treatment of type 2 diabetes mellitus. MET's antihyperglycemic action depends at least in part on its inhibitory effect on hepatic gluconeogenesis. As to gluconeogenesis from amino acids (e.g. L-alanine), this is associated with an inhibition of L-alanine uptake into hepatocytes. Since this uptake is mediated by an electrogenic transport mechanism, the aim of the present study was to investigate whether MET has an influence on the liver cell membrane potential which might explain its inhibitory effect on L-alanine uptake. The experiments were performed in vivo in anesthetized rats and in vitro using superfused mouse liver slices with the conventional microelectrode technique. In vivo, MET (160 mg/kg intraperitoneally (i.p.)) significantly depolarized (dV) the liver cell membrane by 6 mV. MET (1 mmol/l) also depolarized the liver cell membrane in vitro (e.g. 15 min after start of superfusion: dV=8 mV). MET's effect was at least partly reversible. Glucagon (10(-7) mol/l), which hyperpolarized the liver cell membrane, abolished MET's effect. Further, the MET-induced depolarization was completely absent during superfusion with low Cl(-) ([Cl(-)]=27 mmol/l) medium, and significantly attenuated by the Cl(-) channel blocker NPPB (25 micromol/l). While MET's effect was only somewhat attenuated by blockade of the Na(+)/K(+)/2Cl(-) cotransporter or by superfusion with (HCO(-)(3)-free) HEPES buffer, the carboanhydrase blocker acetazolamide (1 mmol/l) or blockade of the HCO(-)(3)/Cl(-) exchanger by DIDS (100 micromol/l), which, however, also blocks Cl(-) channels, abolished its effect. The depolarization of the liver cell membrane by MET was unaffected by a blockade of K(+) channels with Ba(2+), a blockade of the Na(+)/K(+) pump or superfusion with low Na(+) medium ([Na(+)]=26 mmol/l). According to these results, the MET-induced depolarization of the liver cell membrane could be due to an activation of the Cl(-)/HCO(-)(3) exchanger and thus depend on intracellular HCO(-)(3) formation. This activation could then lead to a disturbance of the equilibrium between intra- and extracellular Cl(-) and therefore to an enhanced Cl(-) efflux via Cl(-) channels. It is plausible that the depolarizing effect induced by MET is associated with its inhibitory effect on gluconeogenesis by inhibiting uptake of L-alanine and other amino acids into hepatocytes.

Two new tailoring enzymes, a glycosyltransferase and an oxygenase, involved in biosynthesis of the angucycline antibiotic urdamycin A in Streptomyces fradiae Tü2717

Urdamycin A, the principal product of Streptomyces fradiae Tu2717, is an angucycline-type antibiotic and anticancer agent containing C-glycosidically linked D-olivose. To extend knowledge of the biosynthesis of urdamycin A the authors have cloned further parts of the urdamycin biosynthetic gene cluster. Three new ORFs (urdK, urdJ and urdO) were identified on a 3.35 kb fragment, and seven new ORFs (urdL, urdM, urdJ2, urdZl, urdGT2, urdG and urdH) on an 8.05 kb fragment. The deduced products of these genes show similarities to transporters (urdJ and urdJ2), regulatory genes (urdK), reductases (urdO), cyclases (urdL) and deoxysugar biosynthetic genes (urdG, urdH and urdZ1). The product of urdM shows striking sequence similarity to oxygenases (N-terminal sequence) as well as reductases (C-terminal sequence), and the deduced amino acid sequence of urdGT2 resembles those of glycosyltransferases. To determine the function of urdM and urdGT2, targeted gene inactivation experiments were performed. The resulting urdM deletion mutant strains accumulated predominantly rabelomycin, indicating that UrdM is involved in oxygenation at position 12b of urdamycin A. A mutant in which urdGT2 had been deleted produced urdamycin I, urdamycin J and urdamycin K instead of urdamycin A. Urdamycins I, J and K are tetracyclic angucyclinones lacking a C-C connected deoxysugar moiety. Therefore UrdGT2 must catalyse the earliest glycosyltransfer step in the urdamycin biosynthetic pathway, the C-glycosyltransfer of one NDP-D-olivose.

Finding and treating depression in Alzheimer's patients: a study of the effects on patients and caregivers

Unrecognized and untreated depression occurs frequently in Alzheimer's disease (AD) patients, adding to the agony already experienced by patient and caregiver. The authors screened AD patients living with a family caregiver for depression. Twelve patients with confirmed depression were treated in an open-label study with antidepressant medication, with dosage adjustment by a psychiatrist at Weeks 2, 4, 8, and 16. Data collection occurred at baseline, Week 4, and Week 16. Depression decreased significantly (p < .01). Contrary to expectations, patient functional capacity declined (p = .045). Cognition remained unchanged (p > .05). Caregiver burden, caregiver depressive symptomatology, and quality of life of patient and caregiver remained unchanged (p > .05). The authors conclude that depression in AD can be detected if a collateral source, such as the caregiver, is available. The depression can and should be treated. More research is needed to determine the impact on patient functioning, caregiver burden, caregiver depressive symptomatology, and quality of life of patient and caregiver.

Cloning and characterization of a polyketide synthase gene from Streptomyces fradiae Tü2717, which carries the genes for biosynthesis of the angucycline antibiotic urdamycin A and a gene probably involved in its oxygenation

A DNA fragment was cloned as cosmid purd8, which encodes a polyketide synthase involved in the production of the angucycline antibiotic urdamycin from Streptomyces fradiae Tü2717. Deletion of the polyketide synthase genes from the chromosome abolished urdamycin production. In addition, purd8 conferred urdamycin resistance on introduction into Streptomyces lividans TK24. Sequence analysis of 5.7 kb of purd8 revealed six open reading frames transcribed in the same direction. The deduced amino acid sequences of the six open reading frames strongly resemble proteins from known type II polyketide synthase gene clusters: a ketoacyl synthase, a chain length factor, an acyl carrier protein, a ketoreductase, a cyclase, and an oxygenase. Heterologous expression of the urdamycin genes encoding a ketoacyl synthase and a chain length factor in Streptomyces glaucescens tetracenomycin C-nonproducing mutants impaired in either the TcmK ketoacyl synthase or TcmL chain length factor resulted in the production of tetracenomycin C. Heterologous expression of a putative oxygenase gene from the urdamycin gene cluster in S. glaucescens GLA.O caused production of the hybrid antibiotic 6-hydroxy tetracenomycin C.

[Early gastric cancer, results in a county hospital (author's transl)]

In a nine-year period, 46 patients with early gastric cancer were diagnosed and operated at a county hospital. Fiberscopy of the stomach raised the percentage of early gastric cancer from 1% in a five year pre-endoscopic period to 11.9% with endoscopy. On an average, subjects with early gastric cancer were 8 years younger than all cases with gastric carcinoma, those with the diffuse type according to Laurén significantly younger than those with the intestinal type, too. Postoperative mortality amounted to 6.5%; five more patients of 43 surviving the operation have died in the meanwhile. Besides synchronous and metachronous cancer in the resected stomach and other organs, late distant metastasis must be considered, too, in the follow-up of patients operated from early cancer of the stomach. These complications may endanger the five-years survival rate of 89% observed in the first series of our patients.