[Long-term course of reflux symptoms following Helicobacter pylori eradication]. / Langzeitverlauf von Refluxbeschwerden nach Helicobacter pylori-Eradikation.

BACKGROUND AND OBJECTIVE: Conflicting data regarding new onset or deterioration of gastroesophageal reflux disease (GORD) following eradication of Helicobacter pylori infection have been reported. Successful eradication therapy may influence gastric acid output. The study aimed to to investigate whether patients with pre-existing GORD or peptic ulcer disease may experience deterioration of GORD. PATIENTS AND METHODS: 75 consecutive patients of a prospective longitudinal study (median age 66 years, n = 45 males) had received successful H. pylori eradication therapy because of the following main diagnosis: peptic ulcer (n = 37), GORD (n = 16), functional dyspepsia (n = 22). Two to three years later, they had an interview regarding the course of their dyspeptic and reflux symptoms. Negative H. pylori status at present was confirmed by (13)C-urea breath test in all patients. Ten patients were excluded because of proton pump inhibitor treatment. RESULTS: Patients with deterioration of GORD (new onset or increasing reflux symptoms) were found significantly more frequently in the group with functional dyspepsia (36 %) compared to pre-existing GORD (16 %) or peptic ulcer disease (5 %). Improvement of pre-existing reflux complaints were reported mostly by patients with peptic ulcer disease. There was no significant impact of initial reflux manifestations like reflux symptoms or reflux oesophagitis on the course. CONCLUSIONS: During long-term follow-up after H. pylori eradication, patients experience improvement as frequently as deterioration of reflux symptoms. There is a tendency towards improvement of reflux symptoms if peptic ulcer disease had been the indication for eradication, but towards deterioration in patients with initial functional dyspepsia. A clinical relevant prediction, however, is not feasible.

Proximal median neuropathy and cervical radiculopathy: double crush revisited.

"Double crush" refers to the hypothesis that a single lesion along the course of a nerve predisposes that nerve to a second lesion further along its course. The reason for this is uncertain and indeed the existence of the double crush syndrome is itself debated. We present two cases of proximal median neuropathy (PMN) associated with cervical radiculopathy which we diagnosed in our EMG laboratory over a short period of time. Seeing these cases in relative rapid succession and considering the extreme rarity of PMN, its association in both cases with cervical root disease supports the notion that the cervical radiculopathy may have predisposed the nerve to a second lesion along its course, resulting in the so called double crush syndrome, and that this syndrome may therefore be a true entity.

Differentiation between Phycobiliprotein and Colorless Linker Polypeptides by Fluorescence in the Presence of ZnSO(4).

Microcystis aeruginosa, a unicellular cyanobacterium, contains small phycobilisomes consisting of C-phycocyanin, allophycocyanin, and linker polypeptides. SDS-polyacrylamide gels of the phycobilisomes were examined for fluorescent bands before and after spraying with a solution of ZnSO(4), followed by Coomassie brilliant blue staining for protein. This procedure provides a rapid and sensitive method for detecting small amounts of phycobilin-containing polypeptides and distinguishing them from other tetrapyrrole-containing polypeptides and from ;colorless' ones. Three polypeptide bands, in addition to the alpha and beta phycobiliprotein subunits, have been detected under these conditions. An 85 kilodalton polypeptide was identified as a phycobiliprotein due to its enhanced fluorescence in the presence of ZnSO(4). The other polypeptides do not contain chromophores and are colorless. They are approximately 34.5 and 30 kilodaltons in size.

Glutathione is present in high concentrations in cultured astrocytes but not in cultured neurons.

The levels of the antioxidants, glutathione and ascorbate were measured in primary cultures of murine astrocytes and neurons. The concentration of glutathione (reduced, GSH + oxidized, GSSG) was high in cultured, differentiated (i.e. treated with dBcAMP) and undifferentiated (i.e. untreated) astrocytes: approximately 25 (n = 2) and 16.0 +/- 5.0 (n = 7) nmol/mg protein, respectively. In contrast, glutathione levels in neurons were low: less than or equal to 1.0 (n = 7) nmol/mg protein. Ascorbate could not be detected (less than 2 nmol/mg protein) in either cell type. The apparent lack of defense mechanisms against oxidative stress may in part account for the 'fragility' of neurons in culture. The physiological implications of glutathione compartmentation in brain are discussed.

Fluorometric determination of alpha-ketosuccinamic acid in rat tissues.

A method for the fluorometric determination of alpha-ketosuccinamic acid, the alpha-keto acid analog of asparagine, is described. The procedure involves the hydrolysis of alpha-ketosuccinamate to oxaloacetate by omega-amidase followed by NADH-dependent reduction of oxaloacetate to malate by malate dehydrogenase. A correction for endogenous oxaloacetate is made by using control samples lacking omega-amidase. Of the rat tissues investigated, liver contained the highest concentration, followed by kidney (53 +/- 6 (n = 11) and 18 +/- 3 (n = 3) mumol/kg wet wt, respectively). alpha-Ketosuccinamate was not detected in brain (less than 8 mumol/kg wet wt). Some chemical properties of alpha-ketosuccinamate were investigated. Concentrated solutions of sodium alpha-ketosuccinamate frozen for extended periods and the solid sodium salt of alpha-ketosuccinamate dimer heated to 130 degrees C are converted to at least 10 products by processes involving dimerization, dehydration, and decarboxylation. Isobutane chemical ionization mass spectral analysis (170-230 degrees C) of the free acid monomer yielded similar products. Many of the breakdown products were identified as di- and monoheterocyclic compounds, some of which are known to be of biological importance.

Light Intensity Adaptation and Phycobilisome Composition of Microcystis aeruginosa.

Phycobilisomes isolated from Microcystis aeruginosa grown to midlog at high light (270 microeinsteins per square meter per second) or at low light intensities (40 microeinsteins per square meter per second) were found to be identical. Electron micrographs established that they have a triangular central core apparently consisting of three allophycocyanin trimers surrounded by six rods, each composed of two hexameric phycocyanin molecules. The apparent mass of a phycobilisome obtained by gel filtration is 2.96 x 10(6) daltons. The molar ratio of the phycobiliproteins per phycobilisome is 12 phycocyanin hexamers:9 allophycocyanin trimers. The electron microscopic observations combined with the phycobilisome apparent mass and the phycobiliprotein stoichiometry data indicate that M. aeruginosa phycobilisomes are composed of a triangular central core of three stacks of three allophycocyanin trimers and six rods each containing two phycocyanin hexamers. Adaptation of M. aeruginosa to high light intensity results in a decrease in the number of phycobilisomes per cell with no alteration in phycobilisome composition or structure.

Adaptation of the Cyanobacterium Microcystis aeruginosa to Light Intensity.

Light intensity adaptation (20 to 565 microeinsteins per square meter per second) of Microcystis aeruginosa (UV-027) was examined in turbidostat culture. Chlorophyll a and phycocyanin concentrations decreased with increasing light intensity while carotenoid, cellular carbon, and nitrogen contents did not vary. Variation in the number but not the size of photosynthetic units per cell, based on chlorophyll a/P(700) ratios, occurred on light intensity adaptation. Changes in the numbers of photosynthetic units partially dampened the effects of changes in light intensity on growth rates.

The differential scattering of circularly polarized light by chloroplasts and evaluation of their true circular dichroism.

Chloroplasts isolated from pea leaves display an intense circular dichroism in the range 600 to 720nm. Circularly polarized light is also differentially scattered by chloroplasts, and this effect can be confused with circular dichroism. By using an instrumental modification it was possible to distinguish, and record separately, the ellipticities of the transmitted light (circular dichroism) and of the scattered light in the same c.d. instrument. By means of a light-scattering apparatus, the intensity of unpolarized light scattered by chloroplasts was measured as a function of wavelength and of angle. This measurement allowed the aforementioned ellipticities to be corrected for mutual interference. At a concentration of 4mug of chlorophyll/ml (the optimum practical concentration of chloroplasts at which there was no significant interaction of scattering and absorption effects) spectra of true circular dichroism (circular differential absorption) and circular differential scattering were obtained. The former showed maxima, positive at 688nm and negative at 676nm, with an intensity Deltatheta=8.3m degrees .litre.(mg of chlorophyll)(-1).cm(-1). The latter had a maximum at 683nm with an intensity of +47m degrees with respect to the solvent baseline; this value is independent of the concentration of chloroplasts in dilute suspensions. It is suggested that the intense circular dichroism of chloroplasts reflects specific chlorophyll-chlorophyll interactions in the light-harvesting pigment. The advantages of this method for determining the c.d. of scattering suspensions over those of other investigators are discussed.