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Describes Australian study which investigated relationships between characteristics of disadvantaged elementary and secondary students and their participation in computing activities, both in and out of the classroom. Variables used to define disadvantaged include gender, school ability, socioeconomic status, and ethnic background. Results are analyzed, and 53 references are provided. (Author/LRW)

The size and distribution of Cortinarius rotundisporus genets at three sclerophyll forest field sites in New South Wales, Australia, were estimated by using microsatellite-primed PCR (MS-PCR) of DNA extracted from sporocarp tissue. MS-PCR fingerprints generated with the primers (GTG)5 and (GACA)4 indicated that two to five genets were present at each site, with each site being characterized by a single large genet (9 30 m in diameter). Analysis of internal transcribed spacer (ITS)-RFLP patterns from individual sporocarps used in the study suggested that three distinct RFLP types were present in the sampled C. rotundisporus population. ITS sequence data indicate that the three RFLP types had less than 88.4% sequence identity to each other, strongly suggesting that C. rotundisporus is a complex of three species. [ABSTRACT FROM AUTHOR]

One hundred and sixty-eight sterile endophytic mycelia were isolated from roots of four Woollsia pungens (Cav.) F. Muell. (Epacridaceac) plants collected from a field site in New South Wales, Australia. All isolates formed typical ericoid rnycorrhizal structures when inoculated onto Toots of Vaccinium macrocarpan Air. (Ericaccae). Microsatellite-primed PCR fingerprints generated using the primers (GTG)5, and (GACA)5, indicated that considerable genetic diversity exists within the endophyte population. it was estimated that a minimum of 43 genetically distinct mycclial genets were present in the root systems of the sampled W. pungens population, with most genets confined to individual plants. Two genets, however, were present within the root systems of two adjacent plants. While most genets were represented by less than eight isolates, three genets contained up to 41 isolates, suggesting that root system colonization by some endophytic mycelia might be extensive. [ABSTRACT FROM AUTHOR]

Sixty-two isolates of Pisolithus were obtained from a carpophore population collected from a 90-km² area of New South Wales, Australia. Random amplified polymorphic DNA (RAPD) analysis was used initially to screen isolates for variation, and restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer (ITS) region and ITS sequence analysis were subsequently performed on selected isolates. TTS-RFLP and ITS sequence analysis indicated that two isolates (LJ07 and WM01) from different sites were considerably different from all other isolates, a strict consensus tree generated by bootstrap analysis of sequence data strongly suggesting that isolates LJ07 and WM01 represent a separate Pisolithus species. Although the general morphology of carpophores and basidiospores of the majority of collected isolates was consistent with previous descriptions of P. tinctorius (Pers.) Coker and Couch, basidiospore characteristics suggest that isolates LJO7 and WMO1 might represent a Pisolithus species distinct from P. tinctorius and the previously described Australian species, P. microcarpus (Cooke & Massee) G. Cunn. [ABSTRACT FROM AUTHOR]

The internal transcribed spaced (ITS) region of the nuclear ribosomal RNA was amplified, cloned and sequenced from spores of five isolates of the arbuscular mycorrhizal fungus Glomus mosseae and one isolate each of G. fasciculatum, G. dimorphicum and G. coronatum. The sequences comprised ITS1 (113-121 base pairs), 5.8S rRNA gene (154 base pairs) and ITS2 (222-230 base pairs). The ITS sequences were at least 84% identical, but only distantly related to other published sequences. Their identification as Glomus sequences was confirmed by sequencing part of the adjoining SSU rRNA gene from one isolate; it was 98% identical to the published G. mosseae sequence. Two to four clones were sequenced form each isolate, and in many instances these were substantially different (up to 6% divergence) even when they were obtained form a single spore. Sequences from a single isolate were generally, but not always, more similar to each other than to those from different isolates. In addition to base substitutions, many ITS sequences differed slightly in length because of the insertion or deletion of up to three nucleotides within short runs of a single base, generally A or T. These changes were found at 22 separate sites within the ITS, and more common between than within isolates. Phylogenetic relationships deduced from length variation and from base substitution were similar. The variation among isolates from different continents (Europe, Asia, South America) was no greater than among those from a smaller geographic range. The ITS1 and 2 sequences from G. coronatum were clearly distinct from the other isolates (11-16% divergence), but those of G. fasciculatum and G. dimorphicum fell within the range of variation exhibited by G. mosseae. [ABSTRACT FROM AUTHOR]

Three fungi, isolated from soil from which Phytophthora was not obtained, were evaluated for antagonism of Phytophthora spp. shown to cause root rot of chestnut in South Australia. Trichoderma hamatum and T. pseudokoningii appeared to inhibit P. cinnamomi by mycoparasitism, with evidence of parallel growth and coiling, and both Trichoderma spp. and Gliocladium virens grew over P. cinnamomi in vitro, preventing further growth of this pathogen. Antibiotics produced by young T. hamatum cultures and G. virens in culture filtrate experiments inhibited growth of P. cinnamomi and P. citricola, with filtrate from 4-day-old cultures of G. virens showing the greatest potential for biocontrol. All three antagonists prevented P. cinnamomi and P. citricola from causing infection symptoms on micropropagated shoots of chestnut cvs Goldsworthy and Buffalo Queen in an in vitro excised shoot bioassay for biocontrol. [ABSTRACT FROM AUTHOR]

Isolates of the endomycorrhizal fungus Hymenoscyphus ericae and the ectomycorrhizal fungus Hebeloma crustuliniforme from soils uncontaminated with AsO34, were compared with regard to their sensitivity to AsO34 in solution culture. When grown in liquid media amended with a range of AsO34 concentrations, H. ericae demonstrated reduced sensitivity to AsO34 compared to H. crustuliniforme. The concentrations causing 50% inhibition of growth (EC50) were 1.33 mol/m3 and 0.33 mol/m3, respectively, for H. ericae and H. crustuliniforme. The compound AsO34 is a PO34 analogue for the plasmalemma PO34 transporter. The presence of PO34in the media at high concentrations ameliorated the toxic effects ofAsO34 in both the ericoid and ectomycorrhizal fungi. This could be due to both suppression of the PO34 transporter under high phosporus status and competition of PO34 with AsO34 for the transport protein. The kinetics of AsO34 influx in H. ericae and H. crustuliniforme were also investigated. Hymenoscyphus ericae demonstrated a high Km value, 0.071 mol/m3, consistent with values obtained for AsO3-4tolerant plants. We suggest that the high Km value maybe a mechanism used by H. ericae to express reduced AsO34 sensitivity. The ecological significance of this reduced sensitivity is also discussed. [ABSTRACT FROM AUTHOR]

Background/aim: Alpha-1-antitrypsin deficiency (alpha1ATD) is the commonest metabolic disease leading to liver transplantation (LT) in children. Approximately 10-15% of the PiZZ population develops liver disease. Five percent of them will require LT within the first 4 years of life. This study aimed to investigate the prognosis of the liver disease associated with PiZZ alpha1ATD in the era of liver transplantation and to determine predictors of outcome., Methods: We reviewed retrospectively the clinical notes of 97 consecutive patients referred from January 1989, when LT became routinely available in our Unit, to July 1998., Results: Of 26 (27%) patients who developed end-stage liver disease, 24 have been transplanted and two are waiting for LT. Twenty-one (81%) of these patients presented with neonatal hepatitis at a median age of 2.1 months. Of 71 (73%) children who have not required LT, 61 (86%) presented with neonatal hepatitis at a median age of 1.6 months. Among infants with neonatal hepatitis who required LT, 18 out of 21 (86%) had jaundice for more than 6 weeks compared with 34 of 61 (56%) who survived without LT (p<0.01). Children requiring LT had higher aspartate aminotransferase (AST) at presentation (p<0.0001) and both higher AST and gamma-glutamyl transferase (GGT) at 6 months (p<0.001), 1-year (p<0.0003) and 5-year (p<0.01) follow up when compared to those who are well without LT. Furthermore, children who developed end-stage liver disease more frequently had severe bile duct reduplication (p<0.01), severe fibrosis (p<0.03) with bridging septa (p<0.02) and established cirrhosis (p<0.04) in the initial liver biopsy. Ninety-five of the 97 children (98%) are currently alive; two died after LT., Conclusions: The advent of liver transplantation has significantly improved the prognosis of liver disease associated with PiZZ alpha1ATD. Duration of jaundice, severity of histological features and biochemical abnormalities predict outcome at an early stage of the disease.

The partition coefficients for the distribution of bilirubin between aqueous phosphateborate buffer and cholic, taurocholic, taurodeoxycholic, and taurochenodeoxycholic micelles have been measured by micellar electrokinetic chromatography at pH 8.5. Determination of the partition coefficients required that the critical micelle concentration and partial specific volumes be determined for each bile salt. Critical micelle concentrations were slightly higher for the trihydroxy bile salts. Partial specific volumes of the bile salt micelles differed very little from each other, and for each bile salt they were constant over the concentration range studied, which was typically from slightly above the critical micelle concentration to 35 mM. Capacity factors were corrected for the effects of applied voltage by extrapolation of the capacity factor to zero applied volts. The free solution mobility of bilirubin, determined in the absence of bile salt, was also corrected for the effects of applied voltage. Plots of extrapolated capacity factor versus phase ratio yield the partition coefficient as the slope of a linear fit to the data. Partition coefficients for bilirubin were significantly higher for dihydroxy bile salts than for trihydroxy bile salts.

The mother and second child from a family, already with one PI ZZ child, were typed PI MZ by isoelectric focusing and unexpectedly as PI ZZ using a commercial alpha-1-antitrypsin genotyping kit. Both methods typed the father and first child as PI MZ and PI ZZ, respectively. DNA sequence analysis identified a 26-base pair (bp) deletion and 2-bp insertion in intron IV of the normal PI*M allele from both the mother and second child. The majority of the binding site for an amplification primer of the genotyping kit was absent in the variant deletion-insertion allele. The apparent PI*Z/PI*Z genotype of the mother and second child therefore arose from amplification of the PI*Z allele alone. Two hundred random DNA samples were subsequently examined and 5 of these were found to be heterozygous for the same deletion-insertion allele. The authors have designated the previously undescribed PI*M allele that harbors this benign polymorphism PI*Mwhitstable. The genotyping kit has been redesigned and revalidated, and its performance is not affected by the presence of the PI*Mwhitstable allele. The Gen Bank accession number for the nucleotide sequence described is AF159454.

Cystic fibrosis is a common disease of the Caucasian population and is associated with significant early mortality. We present a simple and rapid method for cystic fibrosis genotyping from filter paper blood spots, using a currently available commercial genotyping kit. Using multiplex technology, genotype information on the four most common UK mutations can easily be obtained within a single working day. Used in conjunction with current immunoreactive typsinogen screening protocols, blood spot genotyping offers a method of hastening the diagnosis, and thus treatment, of cystic fibrosis.

1. A missense mutation leading to reduced ligand affinity in the glucagon receptor (GCG-R) has been found recently to be five-fold more common in essential hypertensives than normotensives. The present paper provides additional information on patients that harbour this variant and proposes a possible mechanism by which this may lead to hypertension. 2. The seven hypertensives with the mutation were all female, had a later age of onset of the disease and a slightly higher body mass index. 3. Glucagon is involved in the regulation of fluid and electrolyte excretion. Mutant GCG-R results in reduced ligand affinity and cAMP response which, in the kidney, would reduce the normal natriuretic effect of glucagon. This could lead to enhanced fluid reabsorption, expansion of extracellular fluid volume and hypertension via long-term autoregulation of blood pressure.

Hypothyroidism is associated with both reduced central 5-HT function and an increased incidence of depression. This study tested the hypothesis that the reduced 5-HT function returns to normal with thyroxine replacement therapy. Seven hypothyroid patients were tested before and after adequate thyroxine replacement. Cortisol and prolactin responses to d-fenfluramine, a centrally acting 5-HT-releasing agent, were used as an index of central (hypothalamic) 5-HT responsiveness. 5-HT-mediated cortisol responses were significantly higher after thyroxine replacement. Basal prolactin levels were reduced, but 5-HT-mediated prolactin responses were not significantly higher after treatment, perhaps due to the pre-treatment responses being elevated by the direct stimulatory effects of hypothyroidism itself on pituitary prolactin secretion. Depressive symptomatology improved with thyroxine. TSH levels were positively related to depressive symptomatology, and inversely to cortisol responses. Depressive symptomatology was inversely related to cortisol responses. These findings thus provide further support that central 5-HT neurotransmission is affected by hypothyroidism. They also suggest that the reduction in 5-HT responsiveness is reversible with thyroxine replacement therapy.

Determination of cellular enzyme activities in washout preservation solution used in hypothermic liver graft storage may allow development of an index that could be clinically valuable in prediction of early post-transplant graft function. In the present study, we collected washed out preservation fluid at the time of graft rinsing from 53 liver recipients. Aspartate aminotransferase and, to a lesser extent, lactate dehydrogenase levels correlated with early postoperative graft viability as assessed by 1-month graft survival and standard biochemical indices of liver function. Those patients with the highest aspartate aminotransferase activity in the washout preservation solution experienced the highest levels of this enzyme postoperatively (area-under-the-curve day 1-3; 1340 vs. 788 IU/L), total bilirubin (area-under-the-curve day 1-5; 901 vs. 538 mumol/L), and rejection frequency (67% vs. 31%) (all P < 0.05), with a significantly lower 1-month graft survival rate compared with patients with low effluent levels (62% vs. 92%, P < 0.05). Two markers of endothelial cell damage, purine nucleoside phosphorylase and a creatine kinase isoenzyme, measured in the fluid did not correlate with early graft viability. It is suggested that assay of aspartate aminotransferase activities in preservation fluid washout samples is a clinically useful indicator of graft viability.

At least two proteases are present in the secretion of the pitchers of Nepenthes macferlanei, a major one with an estimated molecular weight of 59000 and a minor one of 21000. The specificity of the major enzyme, nepenthesin, was broader than previously reported, and strikingly similar to that of pepsin. Lipase activity was also demonstrated, while no amylase activity was present.

The topographic and internal anatomy of the sphenoid bone is reviewed with an emphasis on the relationships important to the transcranial and subcranial surgical approaches to the sphenoid sinus, sella turcica and cavernous sinus. A stepwise method of study and dissection is outlined. The equipment and materials needed for sphenoid bone dissection in the laboratory are reviewed.