Are short normal children at a disadvantage? The Wessex growth study.

OBJECTIVE: To examine whether short stature through childhood represents a disadvantage at around 12 years. DESIGN: Longitudinal non-intervention study of the physical and psychological development of children recruited from the community in 1986-7 after entry into primary school at age 5-6 years; this is the second psychometric assessment made in 1994-5 after entry into secondary school at age 11-13 years. SETTING: Southampton and Winchester health districts. SUBJECTS: 106 short normal children (< 3rd centile for height when recruited) and 119 controls of average stature (10th-90th centile). MAIN OUTCOME MEASURES: Psychometric measures of cognitive development, self concept development, behaviour, and locus of control. RESULTS: The short children did not differ significantly from the control children on measures of self esteem (19.4 v 20.2), self perception (104.2 v 102.4), parents'' perception (46.9 v 47.0), or behaviour (6.8 v 5.3). The short children achieved significantly lower scores on measures of intelligence quotient (IQ) (102.6 v 108.6; P < 0.005), reading attainment (44.3 v 47.9; P < 0.002), and basic number skills (40.2 v 43.5; P < 0.003) and displayed less internalisation of control (16.6 v 14.3; P < 0.001) and less satisfaction with their height (P < 0.0001). More short than control children, however, came from working class homes (P < 0.05). Social class was a better predictor than height of all measures except that of body satisfaction. Attainment scores were predicted by class and IQ together rather than by height. Height accounted for some of the variance in IQ and locus of control scores. CONCLUSIONS: These results provide only limited support for the hypothesis that short children are disadvantaged, at least up until 11-13 years old. Social class seems to have more influence than height on children''s psychological development.     

Conditions for selective degradation of lignin by the fungus Ganoderma australis

Summary The white-rot fungus Ganoderma australis selectively degrades lignin in the ecosystem palo podrido. Using conditions that simulate those of palo podrido in the laboratory, it was found that low nitrogen content and low O₂ tension stimulate the productio of manganese peroxidase and lignin degradation, and depress cellulose degradation and cellulase production. The inverse is found at high nitrogen concentration and high O₂ tension. This agrees with previous results indicating that low O₂ tension and low nitrogen stimulate selective lignin degradation by this fungus. Correspondence to: J. Eyzaguirre     

Ultrastructural localization of arachidonic acid in stimulated macrophages

The distribution of 3[H] arachidonic acid incorporated into cultured mouse peritoneal macrophages was assessed upon stimulation of the cells with either the calcium ionophore A23187 or zymosan. After a labeling time of 24 h, cells were stimulated and processed for light and electron microscopic autoradiography. Grains were primarily localized over the plasma membrane and lipid-containing vesicles of both control and stimulated cells. In macrophages stimulated with ionophore, a decreased labeling density was evident in both of these cell compartments. Similar alterations in labeling pattern were observed in zymosan treated cells, although a larger decline in grain density occurred from the plasma membrane compartment. Immunocytochemical localization of PGE2, a major eicosanoid product released upon ionophore stimulation, revealed the presence of the prostaglandin in clear vesicular structures, many of which appear to be continuous with the plasma membrane. These results provide morphological evidence that different cellular pools of arachidonic acid may be differentially mobilized for eicosanoid production as a function of the mode of stimulation.     

THE MATING SYSTEM GENETICALLY AFFECTS OFFSPRING PERFORMANCE IN WOODHOUSE'S TOAD (BUFO WOODHOUSEI)

To determine if the nonrandom, non-resource-based mating system of Bufo woodhousei affects tadpole performance, I performed a series of controlled matings and reared the tadpoles to metamorphosis in the laboratory and field. I asked whether differences in paternal identity, mating status, or body size were related to differences in tadpole mass, larval period duration, metamorphic mass, or survival of offspring. Although both laboratory and field rearings indicated that male and female parentage affected most offspring traits, no correspondence existed between either laboratory and field metamorphic mass or laboratory and field survival of offspring sired by the same male. The lack of correspondence between sire breeding values in the laboratory and field for two of three traits raises doubts as to the validity of drawing conclusions concerning how evolution might be expected to work from laboratory studies. Paternal effects were more pronounced in the field than in the laboratory, despite what is usually presumed to be a greater amount of environmental variation in the field. In the laboratory neither sire body size nor mating status affected any trait, but in the field larger males produced offspring that were 10% heavier at transformation than offspring sired by small males. This predictable relationship between sire phenotype (body size) and offspring performance means that nonrandom mating based on male body size could have a directional effect on offspring performance. Because larger males mate disproportionately often in this population (Woodward, 1982a; Mitchell, unpubl.), the mating system may exert a directional effect on metamorphic body size.     

MICROSPOROGENESIS IN PEANUT (ARACHIS HYPOGAEA)

The stage of pollen development at the time of anther culture is an important factor in the production of haploids. The objectives of the current study were to develop a staining procedure for peanut (Arachis hypogaea L., ssp. hypogaea) microspores, to describe and document the stages of microsporogenesis in peanut, and to confirm a previous report concerning correlations of peanut floral bud shape with stage of microspore development. A staining procedure using propionic carmine provided adequate staining of pollen mother cells, microspores, and pollen. Pollen mother cells and microspores could easily be differentiated by their size and cell wall structure. Plants grown in a controlled environment were found to have highly synchronized microspore development, both within an anther and among anthers contained in the same bud. In addition, floral bud shape was confirmed as a reliable indicator of anther stage in peanuts.     

Uncoupling protein-3 (UCP3) mRNA expression in reconstituted human muscle after myoblast transplantation in RAG2-/-/gamma c/C5(-) immunodeficient mice

Uncoupling protein-3 (UCP3), which is expressed abundantly in skeletal muscle, is one of the carrier proteins dissipating the transmitochondrial electrochemical gradient as heat and has therefore been implicated in the regulation of energy metabolism. Myoblasts or differentiated muscle cells in vitro expressed little if any UCP3, compared with the levels detected in biopsies of skeletal muscle. In the present report, we sought to investigate UCP3 mRNA expression in human muscle generated by myoblast transplantation in the skeletal muscle of an immunodeficient mouse model. Time course experiments demonstrated that 7-8 weeks following transplantation fully differentiated human muscle fibers were formed. The presence of differentiated human muscle fibers was assessed by quantitative PCR measurement of the human alpha-actin mRNA together with immunohistochemical staining using specific antibodies for spectrin and the slow adult myosin heavy chain. Interestingly, we found that the expression of UCP3 mRNA was dependant on human muscle differentiation and that the UCP3 mRNA level was comparable with that found in human muscle biopsies. Moreover, the human UCP3 (hUCP3) promoter seems to be fully functional, since triiodothyronine treatment of the mice not only stimulated the mouse UCP3 (mUCP3) mRNA expression but also strongly stimulated the hUCP3 mRNA expression in human fibers formed after myoblast transplantation. To our knowledge, this is the first time that primary myoblasts could be induced to express the UCP3 gene at a level comparable of that found in human muscle fibers.