Systematic Screening of Adverse Reactions to Metal Debris after Recap-M2A-Magnum Metal-on-Metal Total Hip Arthroplasty.

BACKGROUND AND AIMS: An adverse reaction to metal debris is a known complication after large diameter head metal-on-metal total hip arthroplasty. However, the failure rate varies depending on the implant design. Therefore, we investigated the prevalence of adverse reaction to metal debris, as well as the symptoms and risk factors after undergoing a ReCap-M2a-Magnum large diameter head metal-on-metal total hip arthroplasty. MATERIALS AND METHODS: Between 2005 and 2012, 1188 patients (1329 hips) underwent ReCap-M2a-Magnum total hip arthroplasty at our institution. Systematic screening for adverse reaction to metal debris was arranged using the Oxford Hip Score questionnaire, hip and pelvic radiographs, and assessments of the serum chromium and cobalt ion levels. Clinical evaluation and magnetic resonance imaging were performed for the symptomatic patients, as well as those with either chromium or cobalt ion levels ⩾5 µg/L. The prevalence of adverse reaction to metal debris after ReCap-M2a-Magnum total hip arthroplasty was assessed, and the risk factors for adverse reaction to metal debris were evaluated using logistic regression. The mean follow-up time was 5.2 (0.003-9.1) years. This study was an extension of a previous study conducted at our institution with 80 patients. RESULTS: In total, 33 patients (33 hips, 2.5% of all hips) required a revision operation due to adverse reaction to metal debris. Moreover, 157 hips exhibited definitive adverse reaction to metal debris, but a revision operation was not performed (157 of 1329 hips, 11.8% of all hips). Overall, 190 out of 1329 (14.3%) hips had definitive adverse reaction to metal debris. Pain, subluxation sensation, clicking, swelling, a small head size, and a fair/poor Oxford Hip Score were associated with definitive adverse reaction to metal debris. CONCLUSION: We found a high prevalence of adverse reaction to metal debris in the ReCap-M2a-Magnum total hip arthroplasty patients in this study; however, most of the patients did not require revision operations.

Penicillium subrubescens, a new species efficiently producing inulinase.

Inulin is a reserve carbohydrate in about 15 % of the flowering plants and is accumulated in underground tubers of e.g. chicory, dahlia and Jerusalem artichoke. This carbohydrate consists of linear chains of ß-(2,1)-linked fructose attached to a sucrose molecule. Inulinases hydrolyse inulin into fructose and glucose. To find efficient inulin degrading fungi, 126 fungal strains from the Fungal Biotechnology Culture Collection (FBCC) at University of Helsinki and 74 freshly isolated strains from soil around Jerusalem artichoke tubers were screened in liquid cultures with inulin as a sole source of carbon or ground Jerusalem artichoke tubers, which contains up to 19 % (fresh weight) inulin. Inulinase and invertase activities were assayed by the dinitrosalicylic acid (DNS) method and a freshly isolated Penicillium strain originating from agricultural soil (FBCC 1632) was the most efficient inulinase producer. When it was cultivated at pH 6 and 28 °C in 2 litre bioreactors using inulin and Jerusalem artichoke as a carbon source, inulinase and invertase activities were on day 4 7.7 and 3.1 U mL(-1), respectively. The released sugars analysed by TLC and HPLC showed that considerable amounts of fructose were released while the levels of oligofructans were low, indicating an exoinulinase type of activity. Taxonomic study of the inulinase producing strain showed that this isolate represents a new species belonging in Penicillium section Lanata-divaricata. This new species produces a unique combination of extrolites and is phenotypically and phylogenetically closely related to Penicillium pulvillorum. We propose the name Penicillium subrubescens sp. nov. (CBS 132785(T) = FBCC 1632(T)) for this new species.

Independence of genetic geographical variation between photoperiodic diapause, circadian eclosion rhythm, and Thr-Gly repeat region of the period gene in Drosophila littoralis.

Drosophila littoralis is a latitudinally widespread European species of the Drosophila virilis group. The species has ample genetic variation in photoperiodism (adult diapause) and circadian rhythmicity (pupal eclosion rhythm), with adaptive latitudinal clines in both of them. The possible common genetic basis between the variability of photoperiodism and circadian rhythms was studied by a long-term crossing experiment. A northern strain (65 degrees N) having long critical day length (CDL = 19.9 h) for diapause, early phase of the entrained rhythm in LD 3:21 (psi(LD3:21) = 12.3 h), and short period (tau= 18.8 h) of the free-running rhythm for the eclosion rhythm was crossed with a southern strain (42 degrees N) having short CDL (12.4 h), late eclosion phase (psi(LD3:21) = 20.2 h), and long period (tau= 22.8 h). After 54 generations, including free recombination, artificial selection, and genetic drift, a novel strain resulted, having even more "southern" diapause and more "northern" eclosion rhythm characteristics than found in any of the geographical strains. The observed complete separation of eclosion rhythm characteristics from photoperiodism is a new finding in D. littoralis; in earlier studies followed for 16 generations, the changes had been mostly parallel. Evidently, the genes controlling the variability of the eclosion rhythm and photoperiodism in D. littoralis are different but closely linked. To test for the possible gene loci underlying the observed geographical variability, the period gene was studied in 10 strains covering all the known clock variability in D. littoralis. The authors sequenced the most suspected Thr-Gly region, which is known to take part in the adaptive clock variability in Drosophila melanogaster. No coding differences were found in the strains, showing that this region is not included in the adaptive clock variability in D. littoralis.

The phylogenetic position of Drosophila eskoi deduced from P element and Adh sequence data.

PCR screening with primers specific for the T-, M-, and O-type P element subfamilies was performed to investigate the interspecific distribution in 18 species and to reconstruct the phylogenetic history of the various types within the obscura species group. T-type elements occur in D. ambigua, D. tristis, D. obscura, D. subsilvestris, and D. eskoi. In the genomes of D. subobscura, D. madeirensis, and D. guanche they are present in the form of terminally truncated T-type derivatives. The wide distribution suggests that the T-type subfamily had a long evolutionary history in the obscura lineage. In contrast, the patchy occurrence of M- and O-type elements can be ascribed to four independent events of horizontal invasion of different lineages. The cladogenesis of the obscura group was investigated using a partial sequence of the Adh gene as a marker. In contrast to earlier findings, the position of D. eskoi had to be revised. D. eskoi appears as the closest relative of the D. ambigua clade, whereas D. tsukubaensis is the sister taxon of the species pair D. bifasciata/D. imaii. This result is in good accordance with the P element data, where high sequence similarity (95%) was found among the T-type elements of D. eskoi and those of D. ambigua and D. tristis.

Blue and yellow laccases of ligninolytic fungi.

Extracellular laccases from submerged cultures of Coriolus versicolor BKM F-116, Panus tigrinus 8/18, Phlebia radiata 79 (ATCC 64658), Phlebia tremellosa 77-51 and from cultures of Pa. tigrinus 8/18, Ph. radiata 79 and Agaricus bisporus D-649 grown on wheat straw (solid-state fermentation) were purified. All enzymes from submerged cultures had a blue colour and characteristic absorption and EPR spectra. Laccases from the solid-state cultures were yellow-brown and had no typical blue oxidase spectra and also showed atypical EPR spectra. Comparison of N-terminal amino acid sequences of purified laccases showed high homology between blue and yellow-brown laccase forms. Formation of yellow laccases as a result of binding of lignin-derived molecules by enzyme protein is proposed.

Effects of Temperature on Weak Circadian Eclosion Rhythmicity in Chymomyza costata (Diptera: Drosophilidae).

The adult eclosion rhythms of two Japanese strains of Chymomyza costata were studied in diel thermoperiods of different duration and at different average temperatures. One of the strains had the 'wild-type' photoperiodic larval diapause and the other was a mutant strain lacking the photoperiodic response. At constant temperatures the wild-type strain had weakly rhythmic eclosion in diel photoperiods while the mutant strain was arrhythmic. Free-running rhythms could scarcely be observed at all. The amplitude of the rhythm of both strains was much higher in diel temperature cycles than in corresponding light-dark cycles, and generally higher in continuous darkness than in continuous light. When the average temperature under entraining conditions was lowered, the rhythmicity increased and the median of the eclosion peak was displaced to later hours in the entraining cycle. Both strains were rhythmic at the lowest temperatures, i.e. near 10 degrees C. At low temperatures the majority of the eclosions occurred during the high temperature phase or light phase of the entraining cycle. Although the rhythm started well in the entraining temperature cycles, the subsequent free-running rhythm in constant conditions lasted for only 2-3 days. We concluded that the exceptionally weak rhythmicity of eclosions and the relative importance of temperature cues are adaptive traits which make it possible for this northern species to respond directly to favourable but unpredictable changes in its environment. Copyright 1997 Published by Elsevier Science Ltd. All rights reserved

Characterization of linne, a new autosomal eclosion rhythm mutant in Drosophila subobscura.

A new putative gene, named linne, affecting circadian eclosion rhythm was found in a Norwegian strain of Drosophila subobscura. The phenotype of linne may be novel among Drosophila clock mutants. Eclosion is practically arrhythmic in light-dark cycles, but diel temperature cycles of 4 degrees C amplitude effectively entrain eclosion in continuous light and in continuous darkness. After that, the rhythm continues in constant temperature and darkness, but unlike other strains, it continues in constant temperature and light as well. Thus in the linne strain the coupling between light signals and pacemaker is disrupted, not the pacemaker itself. Genetic effects of linne were tested in crosses with a wild strain. Arrhythmicity was recessive and autosomal and showed monogenic inheritance, suggesting that arrhythmicity in linne is based on mutation on a single locus.

Frequency of multiple insemination in a natural population of Drosophila montana.

The frequency of multiple insemination was studied in a boreal Drosophila montana population using mother-offspring data for a sex-linked allozyme locus. Mating with respect to the marker studied was random. In crowded laboratory cultures the heterozygous offspring had higher viability than homozygotes, but no deviations from Hardy-Weinberg proportions were found in natural populations. In multiply sired progenies the males did not contribute equally to the progeny, but the proportion sired by the second male was 0.76. The estimated frequency of multiple inseminated females was 1.19 +/- 0.31, indicating that practically all the females carried sperm of at least two males. The estimate is the largest ever reported in natural populations of Drosophila. However, the interspecific comparisons may not be relevant, because the frequency of multiple insemination does not necessarily reflect the real lifetime frequency of multiple matings. The effects of local ecology and life history characters, e.g., the uniform age structure and the temporal patterning of matings, on the high degree of detected multiple inseminations are discussed.

Genetic correlation between circadian eclosion rhythm and photoperiodic diapause in Drosophila littoralis.

Populations of Drosophila littoralis are known to be latitudinally highly variable in photoperiodic adult diapause and pupal eclosion rhythm. Phenotypic correlations between the two time-measuring systems among the strains from different latitudes are, however, weak. In the present study, two differing strains were crossed reciprocally in order to search for causal (genetic) correlations between the two traits in the strains. Segregation in the F2 generations showed that variation in each trait was based on a few variable loci only. In the F2, flies having different eclosion times also differed in their diapause. This association was not complete and could have been due to genetic linkage between the traits. For that reason, the hybrid generations were raised for eight generations more to allow recombination between the traits. In F8, selection against diapause was started in the lines by raising them in a light-dark cycle of 15:9, where only females of the southern type reproduce. After eight selected generations, the lines were studied for the traits. Diapause was completely of the southern type, and the eclosion rhythm had also changed in parallel. The change in the phase of the free-running rhythm was not complete. From the present experiment, and from earlier knowledge of the geographical variation in D. littoralis, I conclude that the same pacemaker that is seen in the eclosion rhythm could also participate in daylength measurement for diapause. However, there are also noncorrelated variable parts in the measuring systems of both traits, which may mask the correlated variation.

Genetic polymorphism and evolution in parthenogenetic animals. II. Diploid and polyploid Solenobia triquetrella (Lepidoptera: Psychidae).

Genic polymorphism at sixteen enzyme loci of four different chromosomal races of Solenobia triquetrella (bisexual, two diploid parthenogenetic races and tetraploid parthenogentiic) has been studied by starch gel electrophoresis. Isolated small diploid bisexual populations have rather uniform allele frequencies at all loci which we have studied. Diploid and tetraploid parthenogenetic individuals of this species are in general as heterozygous as bisexual ones. All parthenogenetic local populations are different from each other in the Alps. These parthenogenetic genotypes cannot be derived from a common ancestor through single mutations but rather bear evidence for a polyphyletic origin of parthenogenesis in Solenobia triquetrella. In the marginal distribution areas of the species in northern Europe single genotypes are spread over far larger areas than in the mountain regions of central Europe. This may be due to the old origin of parthenogenesis and polyploidy in northern Europe. No new parthenogenetic and polyploid strains have lately arisen in the regions outside of the Alps.