bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the Phenomenon of Host Adaptation in Salmonella
Authors: Steinbach G. , Lauterbach L. , Methner U. 
Published: March 2003

SummaryTo study the phenomenon of host adaptation in Salmonella, a mathematical model has been developed which permits a definition and experimental investigation of the specific interaction between the adapted serovar and the adequate host. After experimental infection using a mixture of equal parts of two Salmonella strains, A and B, the bacterial concentrations CA and CB were determined in the organs of the animals infected. If an animal of species a and an animal of species b are infected with the same mixture of strain A adapted to a and strain B adapted to b, an expression:may be calculated which describes the influence of the specific serovar‐host interaction on the dynamics of the bacterial count. The variable Qab was determined using four Salmonella dublin, four Salmonellacholeraesuis and five Salmonella gallinarum/pullorum strains in a total of 63 pairs of different hosts (calf and pig, calf and chicken, or pig and chicken). On this basis, the following statements can be made. The epidemiologically defined host adaptation of Salmonellas is accompanied by a specific agent‐host interaction between the adapted serovar and adequate host. It promotes adherence and spreading of the agent in the adequate host. The effect was particularly expressed on day 3 post‐infection and could be detected both in the lumen of the anterior sections of the intestine and in the intestinal lymph nodes and the liver. In part, the host‐independent strain characteristics had a greater influence than the specific serovar‐host interaction on the dynamics of the bacterial count. Strains of non‐adapted serovars may thus result in a more intense colonization and invasion of the host than simultaneously administered bacteria of a serovar which is adapted to the respective host. The effects of a specific serovar‐host interaction on colonization of and spreading in the host should be considered only as a component which contributes to the phenomenon of host adaptation.
Ultrastructural Investigations of Eusperm­atogenesis and Euspermatozoa in Cerithidea obtusa (Lamarck 1822) (Caenogastropoda: Potamididae)
Authors: Suwanjarat Jintamas , Klepal Waltraud 
Published: March 2003

Abstract. Species of the Potamididae occupy the full range of aquatic habitats and differ not only in the morphology and size of their shells but also in sperm morphology. In the past, several species were classified as Cerithiidae. Characters of the developing and the mature spermatozoa have been used to gain better insight into their taxonomy. Cerithidea obtusa (Lamarck 1822) is the most dominant brackish water gastropod of the mangrove forests in Southern Thailand. Spermatological data are scarce in this species. In order to confirm its taxonomic position within the Potamididae, euspermatogenesis and euspermatozoa are examined by transmission electron microscopy. The morphological changes during spermiogenesis such as nucleus condensation, acrosome formation and development of the midpiece are described.
The incidence of opportunistic fungi in patients suspected of tuberculosis
Authors: Chadeganipour M. , Shadzi S. , Dehghan P. , Bijary J. 
Published: March 2003

SummaryThe incidence of opportunistic fungi in bronchoalveolar lavage specimens from patients suspected of tuberculosis in Isfahan, Iran, was determined. From 200 patients 36 yeasts (18%) and seven filamentous fungi (3.5%) were isolated. Out of 44 patients who had fungal infections, 12 cases were affected with definite tuberculosis.
Review of comparative studies between conventional and liposomal amphotericin B (Ambisome®) in neutropenic patients with fever of unknown origin and patients with systemic mycosis
Authors: Blau I. W. , Fauser A. A. 
Published: March 2003

SummaryFungal infections are an important cause of morbidity and mortality in immunocompromised patients. Treatment with amphotericin B is the main therapeutic approach. However, this treatment is limited by the substantial toxicity. We present the data of the first randomized prospective comparative trial in adults (134 patients with fever of unknown origin) with conventional amphotericin B and a liposomal formulation of amphotericin B (AmBisome®, published in 1997 by Prentice et al. (Br. J. Haematol. 98, 711–718) and the data of adults with documented fungal infections (59 patients), treated in this trial. Patients received either conventional amphotericin B 1 mg kg−1 per day, liposomal amphotericin B 1 mg kg−1 per day or liposomal amphotericin B 3 mg kg−1 per day. Patients were entered if they had fever of unknown origin (FUO), defined as temperature of 38 °C or more, not responding to 96 h of systemic broad‐spectrum antibiotic treatment, and neutropenia (<0.5×109 l−1). Efficacy of treatment was assessed, with success defined as resolution of fever for three consecutive days (<38 °C) in the group of patients with FUO and the freedom of clinical signs and/or the elimination of fungus in the group of patients with documented fungal infections. The safety of treatment and renal and hepatic toxicity of liposomal and conventional amphotericin B were compared. No statistically significant difference was found in the treatment efficacy in the three study arms. However, there is a tendency of better treatment results in the two groups of patients, who received liposomal amphotericin B. Thirty‐five per cent of patients with documented fungal infections and 46% of patients with FUO responded to amphotericin B. In the patients group, that received 1 mg kg−1 liposomal amphotericin B it was 63 and 49%, in the group of patients that received 3 mg kg−1 liposomal amphotericin B it was 47 and 64%. Evidence of toxicity due to amphotericin B was seen in 50 patients (83%), toxicity due to liposomal amphotericin B, 1 mg kg−1, was seen in 35 patients (50%), and due to liposomal amphotericin B 3 mg kg−1 in 34 patients (54%). This was a statistically significant difference (P=0.001). It was concluded that liposomal amphotericin B was safer than conventional amphotericin B, but both formulations are equivalent in treatment efficacy. The prophylactic use of amphotericin B in these immunocompromised patients is discussed.
Aspergillus fumigatus– virulence and opportunism?
Authors: Weig M. , Reichard U. , Groß U. 
Published: March 2003

Aspergillus fumigatus– Virulenz und Opportunismus?The Interdisciplinary Forum on Aspergillosis, organized by the Deutsche Gesellschaft für Hygiene und Mikrobiologie (DGHM) section, Eucaryotic Pathogens, and the Deutschsprachige Mykologische Gesellschaft (DmykG), was held at the Georg‐August‐University of Göttingen, Germany, 7–8 April 2000.
In vitro susceptibilities of cerebrospinal fluid isolates of Cryptococcus neoformans collected during a ten‐year period against fluconazole, voriconazole and posaconazole (SCH56592)
Authors: Yildiran S. T. , Fothergill A. W. , Sutton D. A. , Rinaldi M. G. 
Published: March 2003

Summary. We investigated the in vitro susceptibilities of 213 cerebrospinal fluid isolates of Cryptococcus neoformans isolated from 192 patients through a 10‐year period, 1990–99, against fluconazole, voriconazole and posaconazole (SCH56592) by using the NCCLS (National Committee for Clinical Laboratory Standards) macrodilution method, M27‐A. The overall MICs50 and MICs90 of fluconazole, voriconazole and posaconazole were found to be 2 and 8 µg ml−1, ≤0.125 µg ml−1 (both), and ≤0.015 and 0.06 µg ml−1, respectively. The MIC ranges, MICs50, and MICs90 of three triazoles were also determined according to the defined year category (1990–94, 1995, 1996, 1997 and 1998–99). The MICs50 and MICs90 of each triazole remained almost unchanged and did not exhibit any sign of an upward shift during a decade (1990–99). However, a tendency for development of possible cross‐resistance between the three triazoles was observed only in 1996. Meanwhile, the individual relapsing isolates (n:21) from 20 patients exhibited same, higher or, suprisingly, lower MICs, particularly against fluconazole and posaconazole.Zusammenfassung. Wir haben die In Vitro‐ Empfindlichkeit von 213 Cryptococcus neoformans‐Liquorisolaten von 192 Patienten der Zehnjahresperiode 1990–99, für Fluconazol, Voriconazol und Posaconazol (SCH56592) mit der NCCLS‐Makrodilutionsmethode M27‐A AB untersucht. Die MICs50 und MICs90 für Fluconazol, Voriconazol und Posaconazol wurden zu 2 und 8 µg ml−1, 0.125 µg ml−1 (beide), und ≤0.015 und 0.06 µg ml−1 bestimmt. Die MICs50 und MICs90 der drei Triazole wurden auch gesondert in den Jahreskategorien 1990–94, 1995, 1996, 1997, 1998–99 bestimmt. Die Werte der drei Triazole sind während dieses Jahrzehnts (1990–99) fast unverändert geblieben Eine Tendenz zur Entwicklung möglicher Kreuzresistenzen zwischen den drei Triazolen wurde nur 1996 beobachtet. 21 Isolate von 20 Rückfallpatienten zeigen gleiche, höhere oder auch niedrigere MICs, besonders gegen Fluconazol und Posaconazol.
An unusual case of tinea capitis due to Trichophyton soudanense
Authors: Romano Clara , Miracco Clelia , Faggi E. , Cuccia A. , Pini G. 
Published: March 2003

Summary A case of tinea capitis due to Trichophyton soudanense observed in a 4‐year‐old African girl is described. The infection manifested with diffuse pustular lesions of the scalp. Diagnosis was based on culture. Genome study by single primer PCR fingerprinting was also performed. A younger sister, aged 10 months, was the healthy carrier of the mycete.
Variation of resistance to Pseudocercosporella herpotrichoides (Fron) Deighton in wheat genotypes carrying the gene Pch‐1
Authors: Lind V. 
Published: March 2003

AbstractThe effect of the gene Pch‐1 on the resistance of wheat to Pseudocercosporella herpotrichoides was studied at four growth stages. The germplasm used consisted of adapted cultivars, genotypes provided by European plant breeders, near‐homozygous lines and double haploid lines developed from our own breeding projects. The resistance was measured by ELISA. At all growth stages, genotypes carrying Pch‐1 differed significantly in resistance. At early growth stages, there was a strong effect of the gene in most genotypes, but later the effect decreased and significant genotypes‐environment interactions appeared. In addition, minor genes became more important and determined the level of adult plant resistance that proved to be inherited quantitatively. Pch‐1 was of minor importance for this type of resistance. It is concluded that a high and long‐lasting resistance level could be attained if the two genetically different sources of resistance were combined (resistance at juvenile stages, induced by Pch‐1, and quantitative resistance at adult stages).
SCAR and RAPD markers associated with 18‐carbon fatty acids in rapeseed, Brassica napus
Authors: Hu J. , Li G. , Struss D. , Quiros C. F. 
Published: March 2003

AbstractBreeding rapeseed for enhanced oil quality includes the development of varieties with low linolenic acid content. The breeder also aims to develop varieties with a high linoleic acid content because of its nutritional value. Restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) markers have been developed for linolenic acid content, but they are not best suited for a direct application in marker‐assisted selection. The RFLP technique is too complex and time‐consuming and RAPD markers lack codominance, precluding the distinction of homozygous from heterozygous individuals. In this report the conversion of a RAPD marker to a codominant sequence characterized amplified region (SCAR) marker named L1L9 is described. One of the alleles consisting of an 899 bp fragment (allele A), is associated with low linolenic acid content. The other allele consists of an 641 bp fragment (allele B) and is associated with high linolenic acid content. This marker explains approximately 25% of the genetic variation for this trait. Linkage analysis in the mapping population indicates that the SCAR marker probably tags an ω‐3 desaturase gene in B. napus. Two RAPD markers were found to be associated with oleic/linoleic acid content. Markers M14‐350 and I06‐650 explained approximately 10% and 7% of the genetic variation for linoleic acid content, respectively. These two markers were found linked at 12.3cM in the segregating B. napus F2 progeny used for mapping. All the markers reported in this paper should be useful in breeding programmes for developing high linoleic and low linolenic acid rapeseed varieties.
Assessment of genetic and phenotypic variation among intraspecific somatic hybrids of potato, Solanum tuberosum L.
Authors: Gavrilenko T. , Thieme R. , Tiemann H. 
Published: March 2003

AbstractIntraspecific somatic hybrids have been produced by protoplast fusion in eight combinations involving 10 dihaploids (2n= 2x= 24) in an attempt to provide new material for potato breeding. Cytological analysis revealed extensive variation in chromosome number, such as aneuploid, aneusomatic and mixoploid hybrids. Most of the hybrids represented the expected chromosome number of 48; however, the frequency of aneuploids reached 50% in some combinations. Some hybrids carried structurally rearranged chromosomes and exhibited a high frequency of aberrant anaphases. Isozyme and random amplified polymorphic DNA (RAPD) patterns of the hybrids from the same fusion combination were uniform. In the field, somatic hybrids showed wide phenotypic variation in 20 morphological characters. There was a significant correlation between certain leaf characters and the ploidy level, which may be used to distinguish the tetraploid hybrids from hexaploids and octoploids. Tuber yield and flowering intensity were highest in tetraploid hybrids (2n= 4x= 48). Eighteen of the 73 hybrids reached higher yields than the standard variety ‘Adretta’. Floral development and fertility were restored in hybrids derived from fusions between non‐flowering or sterile dihaploids.
Heterotic effects for yield and tuber solids and type of gene action for five traits in 4x potato families derived from interploid (4x‐2x) crosses
Authors: Buso J. A. , Boiteux L. S. , Peloquin S. J. 
Published: March 2003

AbstractThe degree of heterosis for total tuber yield (TTY) and total solids (TS) in 4x‐2x crosses was estimated by comparing the performance of 12 families with their respective parents in two locations in Wisconsin (USA). The parental 2x clones were Phureja‐haploid Tuberosum hybrids with 2n‐pollen production by first‐division restitution. The general combining ability (GCA) and specific combining ability (SCA) were estimated for TTY, TS, vine maturity (VM), length of tuber sprout dormancy (LD), and tuber eye depth (ED). Family performance for TTY ranged from 74 to 146% at Hancock (E#1) and from 77 to 287 at Rhinelander (E#2) when compared with that of the 4x parent group. For VM, the families were late maturing, but a few precocious ones were identified. For TS, the families had heterosis of 5.1% over the 4x parent group. The families had slightly higher ED values than the 4x parents, but families with values within the commercial range were identified. The family average for LD (54 days) was closer to the 2x group (51 days) than to the 4x group (88 days). The direction and magnitude of the parent‐family relationships were variable. The 4x parent TTY was correlated with progeny in E#1 but not E#2. The 2x parent VM had correlation with the offspring at E#2 but not at E#1. The type of gene action had a trait‐specific expression. Significant SCA and GCA variances were observed, suggesting that additive as well as non‐additive genetic effects were operating. The 4x‐2x crosses were able to generate heterotic families for TTY and TS in combination with other useful traits. However, no promising results were found for LD because of the apparent dominance of the short‐dormancy phenotype. This result indicates the need of additional selection and breeding efforts for some specific traits when using S. phureja‐derived germplasm.
Genetic control of seed weight and calcium concentration in chickpea seed
Authors: Abbo S. , Grusak M. A. , Tzuk T. , Reifen R. 
Published: March 2003

AbstractChickpea, Cicer arietinum L., is a staple protein source in many Asian and Middle Eastern countries. Hence, the mineral content of its seed, especially that of calcium, is of nutritional importance. Calcium is transported through plants and to legume pods almost exclusively via the xylem stream, with Ca accretion in developing seeds resulting primarily from diffusion of Ca from the adjoining pod wall. Thus, for seeds of differing surface‐to‐mass ratios, Ca concentration is expected to correlate inversely with seed weight. The relationship between seed weight and Ca concentration in chickpea seeds was studied using a range of germplasm and derivatives from crosses between types differing in seed Ca concentration. Among the cultivars tested, low seed mass was associated with high Ca concentration. However, the study of hybrid progeny indicated that seed Ca content was mainly determined by genetic factors other than grain weight genes. This finding may assist in future breeding of high nutritional quality chickpea cultivars.
Quantitative‐genetic parameters of sorghum growth under striga infestation in Mali and Kenya
Authors: Haussmann B. I. G. , Hess D. E. , Reddy B. V. S. , Mukuru S. Z. , Kayentao M. , Welz H. G. , Geiger H. H. 
Published: March 2003

AbstractTo estimate quantitative‐genetic parameters of sorghum for resistance to the hemi‐parasitic weed striga [Striga hermonthica (Del.) Benth.] and for agronomic traits, 36 diallel F2 populations and their nine parental lines were evaluated under severe striga infestation at two locations each in Mali and Kenya. Location means for grain yield ranged from 132 to 254 g/m2. F2 populations outyielded lines on average by 18%. For striga emergence traits, F2 heterosis values ranged from ‐36% to 232% among populations. Genetic and genotype x environment interaction variances of lines and F2s were highly significant for all traits. Broad‐sense heritabilities for areas under striga severity progress curves and grain yield were 0.83 and 0.90 in lines, and 0.81 and 0.89 in F2s, respectively. General and specific combining ability, and their interaction effects with locations were significant for most traits. F2 superiority for grain yield under striga infestation demonstrates the potential merit of heterozygous cultivars in the target areas. Significant genotype x environment interaction entails multilocational testing to identify stable resistance. A combination of resistance with striga tolerance is recommended to breeders.
Genetic analysis of tocopherol content and composition in winter rapeseed
Authors: Goffman F. D. , Becker H. C. 
Published: March 2003

AbstractThe improvement of the nutritional value and the stability properties of rapeseed oil is partly hindered by the lack of information on the genetic control of tocopherols. The objectives of this investigation were to characterize the inheritance of tocopherols by using two factorial mating designs (North Carolina Design II, NCII). The first (NCII‐A) was produced with two sets of nine parents each, one selected for high and the other for low total tocopherol contents. In the second (NCII‐B), each set consisted of six parents, which were either high or low for the α/γ‐tocopherol ratio. Parents and F1 hybrids from both experiments were tested under field conditions in 1998 and 1999 using a completely randomized design with two replications. Only small differences were detected between mean values of parents and F1 hybrids. General combining ability (GCA) variation in both experiments was highly significant (P < 0.01) for all tocopherol traits. Significant specific combining ability (SCA) effects were only detected for a‐tocopherol in NCIIA and therefore for the α‐/γ‐tocopherol ratio. These results indicate that tocopherol contents and composition are controlled mainly by genes with additive effects. Interactions of F1 hybrids and GCA effects with the environment were significant for only tocopherol contents and not for tocopherol composition.
The influence of a spring habit gene, Vrn‐D1, on heading time in wheat
Authors: Kato H. , Taketa S. , Ban T. , Iriki N. , Murai K. 
Published: March 2003

AbstractThe adaptability of wheat cultivars to environmental conditions is known to be associated with a vernalization requirement, that is, spring/winter habit. To clarify the genetic effect of the spring habit gene, Vrn‐D1, on heading time in the field, recombinant inbred lines (RILs) with or without the Vrn‐D1 gene were produced from F2 plants of the cross between ‘Nanbukomugi’ and ‘Nishikazekomugi’, non‐carrier and carrier cultivars of this gene, respectively. Using growth chambers with a controlled temperature and photoperiod, three components of heading time, i.e. vernalization requirement, photoperiodic sensitivity and narrow‐sense earliness (earliness per se), were evaluated in each RIL. RILs with the Vrn‐D1 gene (E lines) showed greatly reduced vernalization requirements and slightly shorter narrow‐sense earliness than RILs without Vrn‐D1 (L lines), although no difference in photoperiodic sensitivity was observed between the two groups. RILs were planted at four different sites in Japan and examined for their heading time in the field. E lines headed significantly earlier than L lines at all locations, indicating that the earliness of E lines is stable in various environmental conditions. These results indicated that spring habit caused by Vrn‐D1 gene, as well as narrow‐sense earliness, was responsible for heading time in the field.
Winter × spring wheat hybridization ‐ a promising avenue for yield enhancement
Authors: Kant L. , Mani V. P. , Gupta H. S. 
Published: March 2003

AbstractIntrogression of the winter gene pool into spring wheat is being considered as one of the strategies to break through the yield plateau. However, little information is available on the combining ability of these two important but distinct groups of wheats in Indian conditions. Therefore, the present study was undertaken to determine the combining ability and gene action of yield and yield attributes in winter × spring wheat crosses. Seventy F1 progenies developed by 14 winter and five spring wheat lines using a line × tester design were evaluated, along with their parents, for yield and yield attributes in a randomized complete block design under field conditions. The mean squares for all the characters studied showed highly significant differences. The mean squares due to female × male interactions were significant for all the characters studied except for grains per ear and grain weight per ear. Additive genetic effects were found to play a key role in controlling the expression of days to heading, plant height and spikelets per ear.‘MV 19’ and ‘Stepniak’/‘Karvuna’ among winter and ‘PBW 65’ among spring wheats were good general combiners for most of the yield attributes studied. The estimates for specific combining ability effects suggested that, although general combining ability (GCA) effects of most winter wheats are either average or poor, their combination can give desirable genotypes with spring wheat parents possessing a high GCA.