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K Isik

Publications and source records attributed to K Isik.

8 recordsLinked to original sources
PubMed2004

Similarities and effectiveness of test environments in selecting and deploying desirable genotypes.

Rooted cuttings of 40 different clones (genotypes) of Picea abies (L.) Karst were planted in seven test environments (P, H, L, S, B, M and K) in northern Germany. Type-B genetic correlations between the pairs of test sites were estimated, and a cluster diagram based on inter-site genetic correlations for height was used to illustrate the general pattern of similarities among the test sites. Principal component analysis (PCA) showed that the first three principal components explained 97% of the variance in height, thereby providing a good summary of the relationships among the test sites. Test sites B and K accounted for a relatively high-and test sites H and M for a relatively low-proportion of genotype-environment interaction sums of squares and, consequently, for "ecovalence". "Moderator" and "instigator" test sites for interactions in different site combinations were detected. On the basis of several similarity measures, we observed two distinct groups: sites M-S-P formed one group, while sites K-L formed the other; sites H and B were closer to the first group. The empirical data indicated that a good test site should have the following features: (1) low interaction behaviour, (2) low coefficient of variation, (3) high genotypic selectivity, (4) high coefficient of determination, (5) high efficiency of expected gain. Based on these criteria, site M was determined to be the best test site for screening genotypes to be planted in other environments. We concluded that one broadly adapted vegetative propagation population of P. abies can be used for the potential planting environments in northern Germany.

Adaptation, Physiological↗
PubMed2002

The effect of toluidine blue on the survival, dormancy and outer membrane porin proteins (OmpC and OmpF) of Salmonella typhimurium LT2 in seawater.

AIMS: To study the relationship between changes in the composition of the outer membrane proteins and the survival of Salmonella typhimurium LT2 in filtered autoclaved seawater containing Toluidine Blue (TB) dye as a photosensitizer. METHODS AND RESULTS: In samples exposed to TB and excited by artificial visible light, the total viable (TVC) and respiring cell counts (RCC) showed that, although the TVC declined to an undetectable level in 6.5 h, the RCC showed that some cells were still capable of respiration. The porin protein composition changed gradually with OmpC and OmpF becoming undetectable by sodium dodecyl sulphate-polyacrylamide gel electrophoresis after 8 h of incubation. Hydrogen peroxide-pretreated cells survived longer compared with the control. CONCLUSIONS: Oxidative pretreatment of Salm. typhimurium protects cells from some of the effects of sunlight in the presence of photosensitizers. The changes in porin proteins may play a role in this protection. SIGNIFICANCE AND IMPACT OF THE STUDY: The study shows that the survival of bacteria under conditions of stress is the result of a linked series of reactions.

Bacterial Outer Membrane Proteins↗
PubMed2000

Effects of growth hormone replacement therapy on lipids, lipoproteins and apolipoproteins: is the increased apolipoprotein A-1/B ratio the only benefit?

BACKGROUND: The aim of the present study was to investigate the controversial role of growth hormone (GH) therapy in lipid regulation. METHODS: We studied serum levels of cholesterol and subgroups, triglyceride and apolipoprotein A-1 and B in 41 GH-deficient children (with subgroups of untreated and short- and long-term treated subjects) and 20 healthy controls. RESULTS: Cholesterol and low-density lipoprotein cholesterol levels (in mmol/L) were found to be 4.92 +/- 1.34 and 3.02 +/- 1.58 in untreated, 4.15 +/- 0.72 and 2.46 +/- 0.65 in short-term (3 month) treated, 4.93 +/- 1.39 and 3.15 +/- 1.38 in long-term (> 1 year) treated and 4.11 +/- 0.5 and 2.0 +/- 0.74 in control subjects, respectively. The apolipoprotein A-1:B ratio was 1.98 +/- 0.5 in long-term treated and 1.6 +/- 0.6 in control subjects. CONCLUSIONS: The improvement of lipid composition with short-term GH therapy is temporary, but the increase in apo A-1:B is not and seems to be the particular benefit of this therapy.

Adolescent↗
PubMed1999

Nocardia salmonicida nom. rev., a fish pathogen.

An almost complete gene sequence of 16S rDNA of 'Nocardia salmonicida' strain JCM 4826T was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for nocardiae and phylogenetic trees inferred using four tree-making algorithms. The organism and the type strain of Nocardia asteroides consistently formed a monophyletic clade with a distant sequence similarity of 97%. However, previous DNA relatedness experiments showed that strain JCM 4826T and Nocardia asteroides ATCC 19247T belong to different genomic species. The organism was also distinguished from representatives of all validly described species of Nocardia using a combination of phenotypic features. The polyphasic evidence showed that the strain merits recognition as a new species of the genus Nocardia. The name proposed for the new species is Nocardia salmonicida nom. rev.

Animals↗
PubMed1999

Nocardia uniformis nom. rev.

A soil isolate representing the putatively novel species 'Nocardia uniformis' was found to have morphological, staining and chemotaxonomic properties consistent with its classification in the genus Nocardia. An almost complete sequence of the 16S rDNA of the strain was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for nocardiae and phylogenetic trees were inferred using four tree-making algorithms. The organism was consistently associated with the type strain of Nocardia otitidiscaviarum albeit with a relatively low bootstrap value recorded for neighbour-joining analysis. The strain was also readily separated from representatives of all validly described Nocardia species using a set of phenotypic properties. The genotypic and phenotypic data indicate that the strain should be assigned to the genus Nocardia as a new species. The name proposed for the new species is Nocardia uniformis. The type strain is JCM 3224T.

Algorithms↗
PubMed1998

Nocardia, nocardiosis and mycetoma.

The recent emergence of invasive infections due to Nocardia spp., including nosocomial outbreak, is now evident. Newer molecular diagnostic and typing methods are developed. Although sulfonamide-based therapy is generally effective, optimal treatment may be guided by antimicrobial susceptibility testing of isolates. The improved classification of nocardiae and other related genera such as actinomadurae, using the 16S ribosomal RNA sequencing, provide a sound basis for improved diagnostic methods for the identification of members of clinically significant species. The commonest cause of eumycetoma in Sudan is Madurella mycetomatis, and Streptomyces somaliensis and Actinomadura madurae for actinomycetoma. The humoral immunity response in actinomycetoma patients and in experimental mice was measured and significant titre of anti-P24 antibody was demonstrated.

Actinomycetales↗