[The German Medical Devices Information System containing over 100,000 documents]. / Das deutsche Informationssystem Medizinprodukte mit über 100.000 Dokumenten.

The legal foundations, the aims, and the set up of the German Medical Devices Information System are presented. The functioning of the online registration system is demonstrated on hand of the electronic reports relating to certification with respect to section sign 18 Medical Devices Act (MPG). Using the email-based message system, the electronic routes for information are explained. The large amount of data in the medical devices database illustrates the high performance of the continuously developing information system. The future national and European perspectives of the German Medical Devices Information System are described.

The ram1 mutant of Arabidopsis exhibits severely decreased beta-amylase activity.

Despite extensive biochemical analyses, the biological function(s) of plant beta-amylases remains unclear. The fact that beta-amylases degrade starch in vitro suggests that they may play a role in starch metabolism in vivo. beta-Amylases have also been suggested to prevent the accumulation of highly polymerized polysaccharides that might otherwise impede flux through phloem sieve pores. The identification and characterization of a mutant of Arabidopsis var. Columbia with greatly reduced levels of beta-amylase activity is reported here. The reduced beta-amylase 1 (ram1) mutation lies in the gene encoding the major form of beta-amylase in Arabidopsis. Although the Arabidopsis genome contains nine known or putative beta-amylase genes, the fact that the ram1 mutation results in almost complete loss of beta-amylase activity in rosette leaves and inflorescences (stems) indicates that the gene affected by the ram1 mutation is responsible for most of the beta-amylase activity present in these tissues. The leaves of ram1 plants accumulate wild-type levels of starch, soluble sugars, anthocyanin, and chlorophyll. Plants carrying the ram1 mutation also exhibit wild-type rates of phloem exudation and of overall growth. These results suggest that little to no beta-amylase activity is required to maintain normal starch levels, rates of phloem exudation, and overall plant growth.

The sugar-insensitive1 (sis1) mutant of Arabidopsis is allelic to ctr1.

Soluble sugar levels affect a diverse array of plant developmental processes. For example, exposure to high levels of glucose or sucrose inhibits early seedling development of Arabidopsis thaliana (L.) Heynh. Media-shift experiments indicate that Arabidopsis seedlings lose their sensitivity to the inhibitory effects of high sugar levels on early development within approximately two days after the start of imbibition. The sugar-insensitive1 (sis1) mutant of Arabidopsis was isolated by screening for plants that are insensitive to the inhibitory effects of high concentrations of sucrose on early seedling development. The sis1 mutant also displays glucose and mannose resistant phenotypes and has an osmo-tolerant phenotype during early seedling development. The sis1 mutant is resistant to the negative effects of paclobutrazol, an inhibitor of gibberellin biosynthesis, on seed germination. Characterization of the sis1 mutant revealed that it is allelic to ctr1, a previously identified mutant with a constitutive response to ethylene.

The Arabidopsis sugar-insensitive mutants sis4 and sis5 are defective in abscisic acid synthesis and response.

Although soluble sugar levels affect many aspects of plant development and physiology, little is known about the mechanisms by which plants respond to sugar. Here we report the isolation of 13 sugar-insensitive (sis) mutants of Arabidopsis that, unlike wild-type plants, are able to form expanded cotyledons and true leaves when germinated on media containing high concentrations of glucose or sucrose. The sis4 and sis5 mutants are allelic to the ABA-biosynthesis mutant aba2 and the ABA-insensitive mutant abi4, respectively. In addition to being insensitive to glucose and sucrose, the sis4/aba2 and sis5/abi4 mutants also display decreased sensitivity to the inhibitory effects of mannose on early seedling development. Mutations in the ABI5 gene, but not mutations in the ABI1, ABI2 or ABI3 genes, also lead to weak glucose- and mannose-insensitive phenotypes. Wild-type and mutant plants show similar responses to the effects of exogenous sugar on chlorophyll and anthocyanin accumulation, indicating that the mutants are not defective in all sugar responses. These results indicate that defects in ABA metabolism and some, but not all, defects in ABA response can also alter response to exogenous sugar.

Harpin, elicitor of the hypersensitive response produced by the plant pathogen Erwinia amylovora.

A proteinaceous elicitor of the plant defense reaction known as the hypersensitive response was isolated from Erwinia amylovora, the bacterium that causes fire blight of pear, apple, and other rosaceous plants. The elicitor, named harpin, is an acidic, heat-stable, cell-envelope-associated protein with an apparent molecular weight of 44 kilodaltons. Harpin caused tobacco leaf lamina to collapse and caused an increase in the pH of bathing solutions of suspension-cultured tobacco cells. The gene encoding harpin (hrpN) was located in the 40-kilobase hrp gene cluster of E. amylovora, sequenced, and mutated with Tn5tac1. The hrpN mutants were not pathogenic to pear, did not elicit the hypersensitive response, and did not produce harpin.

Intraruminal controlled release of cyromazine for the prevention of Lucilia cuprina myiasis in sheep.

The efficacy of cyromazine, continuously released from intraruminal capsules at dose rates from 0.5 to 2 mg kg-1 d-1, was evaluated against implants of eggs and first instar larvae of Lucilia cuprina on Merino sheep. Estimates from the non-linear relationship between the success of implants and plasma concentrations showed that 95 per cent protection of sheep could be achieved at a mean release rate of 1.39 mg kg-1 d-1 cyromazine which gave rise to a mean plasma concentration of 0.26 mg litre-1. Present formulations allowed protection for about 90 days in a 40 kg sheep. The 'square wave' type of release profile provided negligible suboptimal dosing thus limiting the potential for selection of resistance. Systemic application of cyromazine provides control of covert and overt strike among sheep and could be used in ecologically based strategies for the control of L. cuprina populations.

Efficiency of oxfendazole administered as a single dose or in a controlled release capsule against benzimidazole-resistant haemonchus contortus, Ostertagia circumcincta and Trichostrongylus colubriformis.

Laboratory strains of Haemonchus contortus and Ostertagia circumcincta selected for thiabendazole resistance were found to have a strong side resistance to a single dose of oxfendazole. The LD50 and LD95 in mg of drug per host liveweight were respectively 4.28 and 18.46 mg/kg for H contortus and 3.61 and 11.20 mg/kg for O circumcincta. A field strain of Trichostrongylus colubriformis that had not been selected with thiabendazole for seven years also had a strong side resistance to oxfendazole with approximately 50 per cent of its population resistant to the recommended dose rate of 5 mg/kg. Prolonged administration of oxfendazole by intraruminal controlled release capsules was found to be effective against both susceptible and resistant strains of the above parasites. The first observed effect of oxfendazole, from controlled release capsules, on resistant worms was a decrease in the percentage of eggs developing to third stage larvae. This was followed by a decrease in egg count and in worm numbers.

Controlled release of anthelmintic drugs: a new concept for prevention of helminthosis in sheep.

Anthelmintic effects of oxfendazole continuously released at 0:17, 0.28 and 0.47 mg/kg/day from intraruminal capsules were assessed in groups of sheep artificially infected with Ostertagia circumcincta. Removal of worms was directly related to both release rate and plasma concentrations of drug. At the highest level, worm burdens were removed within seven days of administration and anthelmintic efficiency was 99.9 +/- 0.04, 99.3 +/- 0.5 and 98.9 +/- 0.7 per cent against adult worms, developing fourth stage and early fourth stage larvae respectively. In a field experiment, comparisons were made of the parasitological and animal production differences between groups of weaned lambs which were given no treatment, a single oral dose of 5 mg/kg oxfendazole and capsules releasing either 0.24 or 0.48 mg/kg oxfendazole daily. By four days after administration of capsules worm egg counts were reduced and remained below detectable levels for up to 86 days. Worm counts from 'tracer' and flock sheep showed a reduction in worm numbers, especially for Trichostrongylus spp. Compared with untreated controls, live weight gain and fleece weight of sheep given capsules releasing 0.48 mg/kg oxfendazole daily was increased.

Activity against Ostertagia ostertagi of low doses of oxfendazole continuously released from intraruminal capsules in cattle.

Slow release from intraruminal capsules of 0.48 mg/kg oxfendazole per day for 5.5 days gave percentage efficiencies of 99 +/- 0.6, 86.6 +/- 6.3 and 93.1 +/- 4.5 for the removal of adult worms, developing 4th stages and inhibited larvae of Ostertagia ostertagi respectively. These efficiencies were not significantly different from those obtained from a single oral dose of 2.5 mg/kg. Peak plasma levels of oxfendazole were similar for the 2 types of administration but high levels were maintained longer in cattle given capsules.