Sectoring of fungal colonies induced by low concentrations of fernasan

An inhibitor of Aspergillus flavus has been isolated from peanuts and identified as 5,7-dimethoxyisoflavone. Authentic 5,7-dimethoxyisoflavone, synthesized from benzyl-2-hydroxy-4,6 dimethoxyphenyl (3), and the isolated compound display identical ultraviolet spectra in methanol, in methanol+sodium methoxide, and in methanol+AlCl₃; similar behavior in solvent extraction, column chromatography, TLC, and fungal inhibition.     

Isolation of aflatoxin from Acacia and the incidence of Aspergillus flavus in the Sudan

A series of environmental and clinical isolates of Sporothrix schenckii being studied in our laboratories under standard conditions of temperature, humidity and media, displayed, in some of the isolates, large dematiaceous hyphae. The large hyphae could be seen to produce the fine hyphae associated with S. schenckii on which typical microconidia developed. Typical microconidia also developed occasionally on the large hyphae, and strands of the unusually large hyphae also were seen to form arthroconidia. Some strains formed large, thin-walled cells on thin and/or thick hyphae resembling the balloon cells seen in mature colonies of Trichophyton tonsurans.All strains which have demonstrated these various and unusual structures histopathologically produced typical sporotrichosis in laboratory animals. When reisolated from these animals, the cultures again exhibited the unusual structures, as well as those typical of S. schenckii.     

Big flies, small repeats: the "Thr-Gly" region of the period gene in Diptera

The region of the clock gene period (per) that encodes a repetitive tract of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran species both within and outside the Drosophilidae. All the non- Drosophilidae sequences in this region are short and present a remarkably stable picture compared to the Drosophilidae, in which the region is much larger and extremely variable, both in size and composition. The accelerated evolution in the repetitive region of the Drosophilidae appears to be mainly due to an expansion of two ancestral repeats, one encoding a Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and asparagine or threonine. In some drosophilids the expansion involves a duplication of the pentapeptide sequence, but in Drosophila pseudoobscura both the dipeptide and the pentapeptide repeats are present in larger numbers. In the nondrosophilids, however, the pentapeptide sequence is represented by one copy and the dipeptide by two copies. These observations fulfill some of the predictions of recent theoretical models that have simulated the evolution of repetitive sequences.      

The SF36 health survey questionnaire: an outcome measure suitable for routine use within the NHS?

OBJECTIVE--To assess the validity, reliability, and acceptability of the short form 36 (SF 36) health survey questionnaire (a shortened version of a battery of 149 health status questions) as a measure of patient outcome in a broad sample of patients suffering from four common clinical conditions. DESIGN--Postal questionnaire, followed up by two reminders at two week intervals. SETTING--Clinics and four training practices in north east Scotland. SUBJECTS--Over 1700 patients aged 16-86 with one of four conditions--low back pain, menorrhagia, suspected peptic ulcer, or varicose veins--and a comparison sample of 900 members of the general population. MAIN OUTCOME MEASURES--The eight scales within the SF36 health profile. RESULTS--The response rate exceeded 75% in the patient population (1310 respondents). The SF36 satisfied rigorous psychometric criteria for validity and internal consistency. Clinical validity was shown by the distinctive profiles generated for each condition, each of which differed from that in the general population in a predictable manner. Furthermore, SF36 scores were lower in referred patients than in patients not referred and were closely related to general practitioners'' perceptions of severity. CONCLUSIONS--These results provide support for the SF36 as a potential measure of patient outcome within the NHS. The SF36 seems acceptable to patients, internally consistent, and a valid measure of the health status of a wide range of patients. Before it can be used in the new health service, however, its sensitivity to changes in health status over time must also be tested.     

Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene

We have analyzed the conserved regions of the gene coding for the circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria parasite. The closest evolutionary relative of P. falciparum, the agent of malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is consistent with the hypothesis that P. falciparum is an ancient human parasite, associated with humans since the divergence of the hominids from their closest hominoid relatives. Three other human Plasmodium species are each genetically indistinguishable from species parasitic to nonhuman primates; that is, for the DNA sequences included in our analysis, the differences between species are not greater than the differences between strains of the human species. The human P. malariae is indistinguishable from P. brasilianum, and P. vivax is indistinguishable from P. simium; P. brasilianum and P. simium are parasitic to New World monkeys. The human P. vivax-like is indistinguishable from P. simiovale, a parasite of Old World macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are evolutionarily recent human parasites, the first two at least acquired only within the last several thousand years, and perhaps within the last few hundred years, after the expansion of human populations in South America following the European colonizations. We estimate the rate of evolution of the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year. The divergence between the P. falciparum and P. reichenowi lineages is accordingly dated 8.9 Myr ago. The divergence between the three lineages leading to the human parasites is very ancient, about 100 Myr old between P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between P. falciparum and the other two.      

Survival of Curvularia lunata var. aeria in soil

Spore suspensions from 7 day old cultures of Curvularia lunata (Wakker) Boedijn var. aeria (Batista, Lima and Vasconcelos) M.B. Ellis were added to soil samples originally devoid of Curvularia propagules. The test fungus disappeared after six weeks of inoculation irrespective of soil amendments, like the application of green manure, urea, superphosphate, or soil cropped to Sorghum (dura) or cotton seedlings.     

Studies on the rhizosphere mycoflora of Euphorbia granulata forsk. and E. heterophylla L.

Unlike many higher plants Euphorbia granulata and E. heterophylla do not encourage the development of fungi in their rhizospheres. Fungi recovered therefrom were limited both in number and range of species. The rhizosphere of E. heterophylla was slightly favourable to soil fungi when compared with the other weed plant. Aspergillus niger was least affected by both types of rhizosphere. Expressed latexcontaining sap of E. granulata was remarkably inhibitory to submerged cultures of A. flavus, A. nidulans, Fusarium sp., Curvularia sp. and Helminthosporium. Conidia and mycelial fragments recovered from these cultures failed either to germinate or resume growth thus exhibiting an antifungal property of E. granulata latex.     

Excitation of System I and System II in Photosynthesis as a Possible Control Mechanism of Glycolate Metabolism in the Blue-Green Alga Anacystis nidulans

Photosynthetic enhancement studies performed at 619 nm (excitation of Systems I and II) and at 446 nm (mainly excitation of System I) revealed an 18% photosynthetic enhancement simultaneously with a 31% reduction in glycolate excretion. This observation supports the hypothesis that some glycolate may be consumed in an oxidation process associated with System I when System II is poorly excited and the supply of electrons from the water splitting process of photosynthesis is low.