Pelodera (syn. Rhabditis) strongyloides as a cause of dermatitis – a report of 11 dogs from Finland

Background  

Pelodera (Rhabditis) strongyloides is a small saprophytic nematode that lives in decaying organic matter. On rare occasions, it can invade the mammalian skin, causing a pruritic, erythematous, alopecic and crusting dermatitis on skin sites that come into contact with the ground. Diagnosis of the disease is based on case history (a dog living outdoors on damp straw bedding) with characteristic skin lesions and on the demonstration of typical larvae in skin scrapings or biopsy. Pelodera (rhabditic) dermatitis cases have been reported mainly from Central European countries and the United States.     

Dynamics of Substrate Consumption and Enzyme Synthesis in Chelatobacter heintzii during Growth in Carbon-Limited Continuous Culture with Different Mixtures of Glucose and Nitrilotriacetate

Regulation of nitrilotriacetate (NTA) degradation and expression of NTA monooxygenase (NTA-MO) in the NTA-degrading strain Chelatobacter heintzii ATCC 29600 in continuous culture at a dilution rate of 0.06 h(sup-1) under transient growth conditions when the feed was switched between media containing NTA, glucose, or different mixtures thereof as the sole carbon and energy sources was investigated. A transition from NTA to glucose was accompanied by a rapid loss of NTA-MO. A transition from glucose to NTA resulted in a lag phase of some 25 h until NTA-MO expression started, and approximately 100 h was needed before a steady state for NTA-MO specific activity was reached. This transient lag phase was markedly shortened when mixtures of NTA plus glucose were supplied instead of NTA only; for example, when a mixture of 90% glucose and 10% NTA was used, induction of NTA-MO was detected after 30 min. This suggests a strong positive influence of alternative carbon substrates on the expression of other enzymes under natural environmental conditions. Regulation of NTA-MO expression and the fate of NTA-MO were also studied during starvation of both glucose-grown and NTA-grown cultures. Starvation of NTA-grown cells led to a loss of NTA-MO protein. No synthesis of NTA-MO (derepression) was observed when glucose-grown cells were starved.     

Heat dissociation and maceration of marine Cnidaria

Summary The effect of increased temperature on the tissue integrity of polyps and medusae ofPodocoryne carnea is described. Animals exposed for 10 to 20 min to a temperature of 35°C are easily dissociated into single cells. These dissociated cells round up, form reaggregates and, depending on their origin, regenerate polyp or medusa structures. However, as the exposure time is increased, the dissociated cells gradually lose the ability to reaggregate or to regenerate defined structures. At incubation times exceeding 50 min, the tissue separates into single cells which retain their normalin vivo shapes but which do not form reaggregates. These are termed macerated cells. The ultrastructure and protein profile of macerated cells demonstrate no major changes from those of untreated cells. Both the dissociation and maceration methods are applicable to other cnidarian species for developmental, histological and biochemical studies.     

Tn 5 to assess soil fate of genetically marked bacteria: screening for aminoglycoside-resistance advantage and labelling specificity

Abstract The reliability of Tn 5 as labelling tool was investigated in soil microcosm. The occurence of a selective in soil microcosm. The occurence of resistances encoded by Tn 5 nptII gene was assesed by kanamycin and neomycin amendment. The bioassay developed to monitor the persistence of the soil-added kanamycin did not detect the antibiotic activity in soil extract. A nptII -engineered Escherichia coli strain showed no enhanced survival in aminoglycoside amended soil. Tn 5-marker properties were investigated within indigenous bacteria to determine the specificity of labelling to follow the fate of recombinant DNA. Kanamycin and neomycin resistant population levels made Tn 5 aminoglycoside-resistance phenotype non-sensitive enough to select a soil dissemination of the labelled DNA. The unexpected occurrence of homologous sequences among soil organisms also prevented Tn 5 from being a specific DNA marker. By contrast, colony hybridization did not reveal homology to nptII suggesting its use as a reliable gene transfer indicator.     

Mutation that affects pepN translation initiation in Escherichia coli

Mutants altered in their expression of the hybrid pepN-lacZ gene have been selected for resistance to p-nitrophenyl-beta-D-thiogalactopyranoside (a bacteriostatic compound that enters the cells via lac permease). A unique mutation decreasing the level of pepN expression to 9% of that of the wild type has been studied in detail. This mutation controls in cis the expression of the pepN gene. The pepN region from a pepN-lacZ gene fusion has been cloned and sequenced. Comparison of the mutant and wild type sequences indicates that the mutation lies between the Shine-Dalgarno sequence (AGGT) and the initiation codon (AUG). This mutation is a T----C transition which might allow the formation of a stable secondary structure in the region of translation initiation thus decreasing the level of pepN expression.     

Bases and spaces: resources on the web for accessing the draft human genome - II - After publication of the draft

The volume of human genome sequence and the variety of web-based tools to access it continue to grow at an impressive rate, but a working knowledge of certain key resources can be sufficient to get the most from your genome. This article provides an update to Genome Biology 2000, 1(4):reviews2001.1-2001.5.