Chemical Composition of the Edible Mushroom Pleurotus ostreatus Produced by Fermentation

Pleurotus ostreatus `Florida' was grown in submerged liquid culture. The biomass yield of the fungus, grown for 3 days in 2-liter fermentors, where the mycelial pellets measuring 5 mm in diameter were formed, was 11.7 g (dry weight)/liter. Comparing the chemical constituents of fruiting bodies produced on cotton straw and mycelial pellets revealed several similarities in total nitrogen, protein, glycogen, fatty acids, RNA, and ash content. Differences were observed in the contents of six amino acids. Although the total fatty acid content was similar, there were more saturated fatty acids in the mycelium. Cell wall composition, typical for basidiomycetes, was observed in both mycelium and fruiting bodies, with laminarin as the main polymer.     

Resurgences of spider mites (Acari: Tetranychidae) induced by synthetic pyrethroids

Causes of spider mite (Acari: Tetranychidae) population resurgences consequent upon exposure to synthetic pyrethroid (SP) treatments are reviewed. Resurgences may be seen as soon as 1 week, or even as late as a whole season, post-treatment. Synthetic pyrethroids vary in their adverse effects on spider mites, and also differ in their ability to invoke resurgences of different spidermite species on diverse plants. These pesticides are lethal as well as repellent to phytoseiids and other predators that prey on spider mites, may inhibit fungi which attack the latter, and affect phytophagous competitors. Spider mites are likewise repelled by SPs, thus becoming more evenlydistributed and less web-restricted, with a resultant increase in fecundity. Spider-mite development is shortened due to SPs and the sex ratio becomes more female-biased; onset of winter diapause also seems to be delayed. Synthetic pyrethroids appear to sensitize to spider-mite infestation plants which have not hitherto been attacked. Some SP effects (whether on spider mites, natural enemies or competitors) appear to be direct, whereas others may be mediated through the host plants. The effect of SPs on the other Acari is variable within the Prostigmata and Astigmata. Most Mesostigmata and Metastigmata (ticks) are very sensitive, whilst the Cryptostigmata (Oribatei) appear to be insensitive. Synthetic pyrethroids-induced resurgences of Homoptera are comparatively reviewed, with the conclusion that some of the phenomena may be similar to those observed in spider mites. Various resurgence models are discussed, as well as the three main causes of variation (SPs, spider-mite species, host plants) in the observed phenomena. The need for more rigorous and carefully controlled experimentation is emphasized.     

Comparison of movement and metabolism of indole-3-acetic acid and indole-3-butyric acid in mung bean cuttings

Indole-3-butyric acid (IBA) was much more effective than indole-3-acetic acid (IAA) in inducing adventitious root formation in mung bean ( Vigna radiata L.) cuttings. Prolonging the duration of treatment with both auxins from 24 to 96 h significantly increased the number of roots formed. Labelled IAA and IBA applied to the basal cut surface of the cuttings were transported acropetally. With both auxins, most radioactivity was detected in the hypocotyl, where roots were formed, but relatively more IBA was found in the upper sections of the cuttings. The rate of metabolism of IAA and IBA in these cuttings was similar. Both auxins were metabolized very rapidly and 24 h after application only a small fraction of the radioactivity corresponded to the free auxins. Hydrolysis with 7 M NaOH indicates that conjugation is the major pathway of IAA and IBA metabolism in mung bean tissues. The major conjugate of IAA was identified tentatively as indole-3-acetylaspartic acid, whereas IBA formed at least two major conjugates. The data indicate that the higher root-promoting activity of IBA was not due to a different transport pattern and/or a different rate of conjugation. It is suggested that the IBA conjugates may be a better source of free auxin than those of IAA and this may explain the higher activity of IBA.     

The production of a “universal developer” for the immunological detection of human IgG and its application in immunodiagnostics

Summary This study describes the development of a bispecific monoclonal antibody capable of the simultaneous recognition of horseradish peroxidase (HRP) and human IgG. This antibody, coded McC2, has been applied in a novel manner as a universal developing reagent for the detection of human IgG. McC2 cross-reacts with all human IgG subtypes and was found to recognise an epitope on the Fe portion of human IgG. McC2 does not cross-react with human IgM or IgA. This bi-specific antibody belongs to the mouse IgG₁ subclass. McC2 was used for the detection of human IgG in a simple one step enzyme-linked immunosorbant assay (ELISA). Use of this bi-specific antibody in this assay resulted in an excellent signal to noise ratio with background in negative control wells virtually nonexistent. McC2 was also applied in a clinical diagnostic test for the detection of auto anti-nuclear antibodies in patient sera. McC2 was substituted, in a blind study, for a HRP-conjugated second antibody supplied with the test kit. All sera were tested both with the kit's second antibody and McC2. When using McC2, we obtained no false positive results whereas five false positives were obtained when using the kit's second antibody. However, one false negative result was obtained with the use of McC2 as a developing reagent while none were noted with the use of the kit's second antibody.This study demonstrates the potential use of bi-specific universal developers in a wide variety of immunobased techniques as well as the potential advantages for the production of a complete panel of bi-specific developing monoclonal antibodies against IgGs from a number of different species.     

Development of a bi-specific monoclonal antibody for simultaneous detection of rabbit IgG and horseradish peroxidase: use as a general reagent in immunocytochemistry and enzyme-linked immunosorbent assay

We describe the development of bi-specific monoclonal antibodies (MAb) capable of simultaneous recognition of rabbit immunoglobulin G (IgG) and horseradish peroxidase (HRP) for use in a variety of immunobased techniques. This bi-specific antibody, named McC8, was produced by fusion of the aminopterin-sensitive mouse hybridoma MAP.Ag.1, which secretes MAb against HRP, and splenocytes from a mouse previously immunized with whole rabbit IgG. The resultant hybrid-hybridoma co-dominantly expresses and secretes the immunoglobulin chains, i.e., IgG1 and IgG2b, of its respective parents, as determined by radial immunodiffusion. The binding sites on rabbit IgG for McC8 were determined on Western blots and in competition solid-phase enzymatic immunoassays with the use of allotype-specific rabbit sera. Both these techniques demonstrated that McC8 recognizes the light chain of the rabbit IgG molecule with preferential binding to the B4 kappa light-chain allotype. McC8 was successfully used in two-step immunocytochemistry for localization of calcitonin gene-related peptide (CGRP) in fibers of the superficial layers of the spinal trigeminal nucleus of the rat, as well as for localization of glial fibrillary acidic protein (GFAP)-immunoreactive sites in primary rat septal cell cultures, thus demonstrating its potential as a general developing reagent in conventional immunocytochemistry. McC8 compared favorably with peroxidase-antiperoxidase immunocytochemistry with respect to sensitivity. However, the bi-specific developing reagent proved superior to the conventional peroxidase-antiperoxidase procedure when both were employed in a similar fashion in tissues prone to display high background staining. Finally, McC8 was also employed as a developing reagent in a competitive ELISA designed for quantitation of CGRP with the use of a rabbit anti-CGRP primary antibody. The sensitivity of this quantitative ELISA (190 pg or 50 fmol CGRP per well) renders this bi-specific antibody suitable for use in quantitative immunoassays for detection of relevant peptides in biological systems.     

Numerical investigation of mass transport through patient-specific deformed aortae

Blood flow in human arteries has been investigated using computational fluid dynamics tools. This paper considers flow modeling through three aorta models reconstructed from cross-sectional magnetic resonance scans of female patients. One has the normal control configuration, the second has elongation of the transverse aorta, and the third has tortuosity of the aorta with stenosis. The objective of this study is to determine the impact of aortic abnormal geometries on the wall shear stress (WSS), luminal surface low-density lipoproteins (LDLs) concentration, and oxygen flux along the arterial wall. The results show that the curvature of the aortic arch and the stenosis have significant effects on the blood flow, and in turn, the mass transport. The location of hypoxia areas can be predicted well by ignoring the effect of hemoglobin on the oxygen transport. However, this simplification indeed alters the absolute value of Sherwood number on the wall.     

Two loci on chromosome 9 control bile acid composition: evidence that a strong candidate gene, Cyp8b1, is not the culprit

An intercross between C57BL/6J and CASA/Rk mice was used to study the genetics of biliary bile acid composition. In parental strains, male C57BL/6J mice had significantly higher cholic acid (CA; 14%) and lower beta-muricholic acid (betaMC; 27%) than CASA/Rk mice, whereas females did not differ. However, quantitative trait locus analysis of F2 mice revealed no significant chromosome 9 loci in males but loci in females on chromosome 9 for percentage CA (%CA) at 72 centimorgan (cM) [logarithm of the odds (LOD) 5.89] and %betaMC at 54 cM (LOD 4.09). Chromosome 9 congenic and subcongenic strains representing CASA/Rk intervals 38-73 cM (9KK) and 68-73 cM (9DKK) on the C57BL/6J background were made. In 9KK and 9DKK males, %CA was increased and %betaMC was unchanged, whereas in 9KK but not 9DKK females, %CA was increased and %betaMC was decreased. Sterol 12alpha-hydroxylase (Cyp8b1) channels bile acid precursors into CA and maps at chromosome 9 (73 cM). However, there was no significant difference in Cyp8b1 mRNA or enzymatic activity between parental mice, parental-congenic-subcongenic mice, or high-low biliary %CA F2 mice. In summary, two chromosome 9 loci control sexually dimorphic effects on biliary bile acid composition: a distal (68-73 cM) major determinant in males, and a more proximal (38-68 cM) major determinant in females. In this intercross, Cyp8b1, a strong candidate, does not appear to be responsible.