Relation of body fat distribution to hyperinsulinemia in children and adolescents: the Bogalusa Heart Study

The relation of body fat distribution to plasma levels of glucose and insulin during an oral glucose tolerance test was examined in 355 Black and White school-age children. Both central and peripheral fat were similarly related to fasting, 30-min, and 1-h glucose. Unlike peripheral fat, central body fat was more strongly related to the 1-h insulin response (r = 0.35 vs 0.26); this association remained significant for central fat independent of peripheral fat (r = 0.18). The strong relation of central fat to insulin response was noted in both races and sexes but not in either sexually immature or relatively thin children. These findings indicate that, even in early life, a central body fat pattern relates positively to insulin response to glucose load. Thus, knowledge of body fat localization may help identify persons most susceptible to hyperinsulinemia in early life.     

Prospective serial analysis of interleukin-2 and soluble interleukin-2 receptor in relapsing-remitting multiple sclerosis.

We performed a longitudinal analysis of serum interleukin-2 (IL-2) and soluble IL-2 (sIL-2R) concentrations in 60 patients with relapsing-remitting (R-R) multiple sclerosis (MS) as well as in 33 age- and sex-matched normal controls. Overall, we found that serum IL-2 levels remained low (less than 10 U/ml) and did not change appreciably over time; however, marked fluctuations in sIL-2R levels were observed in both the patient and control groups. Using patients as their own controls, we calculated an interrelapse (disease stable) mean sIL-2R concentration as a baseline for comparison with relapse values; sIL-2R levels greater than the 90th percentile of the Student's t distribution of stable values were defined as "peaks." There were a total of 27 sIL-2R peaks, eight (30%) of which correlated with clinical relapses but were potentially predictive of only 18% (8/45) of all the recorded clinical relapses. There was no difference in disease severity (Expanded Disability Status Scale) score between peak-correlated and noncorrelated relapses. Our data suggest that despite reports of elevated levels of IL-2 and sIL-2R in MS, neither may be a useful marker for predicting clinical disease activity in R-R MS.     

Joint custody: historical, legal, and clinical perspectives with emphasis on the situation in Canada

The search for ways to mitigate the effects of family breakdown on parents and children includes legislative and clinical efforts which to some extent influence each other. In the past year much public interest has been aroused in Canada, and particularly in Ontario, in the issue of legislative changes which would make joint custody the usual or "preferred" legal disposition of custody cases. This paper provides a discussion of the legislated preference, or "rebutable presumption" of joint custody from a historical, legal and clinical point of view. Definition and elaboration of what joint custody is from the legal and practical perspectives is provided with an emphasis on Canadian laws and practice. The legal rights of the non-custodial parent are explained, and relevant case law is highlighted. The relationship between joint custody, support orders and relitigation rates are elaborated. Following this is a critical overview of the empirical research on joint custody as it relates to the adjustment of children and parent satisfaction is included. It is concluded that while there is little question that shared parenting can be beneficial to children, the enthusiasm of legislators for joint custody has not been supported by empirical data. It is necessary to examine under what circumstances and for which kinds of parents and children joint custody might be beneficial since it is unlikely that one solution will fit the needs of all families and all stages of family life.     

Contrast sensitivity in humans with abnormal visual experience.

1. Grating contrast sensitivities have been determined over a range of spatial frequencies for a normal subject and for subjects who are visually biased in that they have a lower resolution capacity for targets of specific orientations. The bias si only found in astigmatic subjects and the grating orientation yielding poorest acuity coincides with the most defocused astigmatic meridian. However this resolution anisotropy remains when optical factors are accounted for. 2. For the normal subject, high and low frequency attenuation is found and a typical reduction in contrast sensitivity is exhibited for oblique target orientations. 3. The biased subjects, called meridional amblyopes because they have reduced acuity for a given grating orientation, show markedly abnormal contrast sensitivity functions. Their cut-off spatial frequencies are different for various target orientations and this difference applies also to contrast sensitivity over nearly the entire spatial frequency range tested (0-5-16 cycles/deg). The differences are of about the same magnitude for most frequencies and they are found in all types of meridional amblyopes. 4. Optical explanations of these differences are ruled out by laser-interference fringe tests and by varying effective pupil size. 5. Theoretical effects of defocus have been calculated to compare predicted visual deprivation with performance. Results indicate that reduced contrast sensitivity functions can be equivalent to a small defocus effect. 6. To examine the results in the spatial domain, inverse Fourier transforms of representative contrast sensitivity functions have been computed. The optical portion of the resulting spatial weighting functions has been parcelled out to obtain neural spatial weighting functions.     

Quantification of antibodies to the C3d subcomponent of human C3.

Purified soluble C3d has been employed to measure the concentration of anti-C3d antibodies in immune rabbit sera. Multiple batches of C3d, prepared from C3-C3b substrate by treatment with C3b-inactivator (KAF), after labelling with 125I, retained 80% immunoreactivity, and were stable on storage at -50 degrees and +4 degrees. Concentrations of anti-C3d were determined by Scatchard analysis of equilibrium concentrations of bound and free C3d in a mixture of 125I-labelled C3d and anti-C3d. Separation of bound from free C3d was by G-75 Sephadex filtration. Assuming a 1:1 molar ratio in the antibody-C3d complex, anti-C3d antibody concentrations for four rabbit whole antisera and four IgG preparations fell in the range 288-2433 microgram/ml, with Ko values of 6-2 X 10(8)-2-9 X 10(9) litres/mol. One commercial antiglobulin-serum contained 3-6 microgram anti C3d/ml and had a Ko value of 1-7 X 10(8) litres/mol. Values for anti-C3d concentrations measured independently by an indirect method employing 125I-labelled sheep anti-rabbit IgG averaged 20% lower than those obtained with 125I-labelled C3d. Antibody concentrations were correlated with antiglobulin agglutination titres against C3d-coated red cells; a titre of 1 was given by an anti-C3d concentration of 0-5 microgram/ml.     

EA rosette-forming lymphoid cells in chickens: specificity of the Fc receptor and its relationship to other surface antigens.

The receptor for erythrocyte-antibody (EA) complexes on the surface of chicken lymphoid cells was investigated using a rosette assay. The chicken EA receptor binds chicken immunoglobulin of the IgG class but not the IgM class. Binding to the EA receptor is dependent upon the Fc region of the immunoglobulin. No receptor for complement analogous to the mammalian C3b receptor was demonstrated on chicken lymphoid cells using the rosette assay. Inhibition studies utilizing immunoglobulins from several species demonstrated that chicken spleen cells do not bind mammalian immunoglobulin but may bind immunoglobulin of other avian species (turkey and duck) and a reptilian species (turtle). The chicken EA receptor is distinct from cell membrane bound immunoglobulin light chains, bursa-specific antigens and thymus-specific antigens. The receptor for EA complexes on chicken lymphoid cells is compared with the Fc receptor on mammalian lymphoid cells in the light of these observations.     

Nutritional effects on host response to lung infections with mucoid Pseudomonas aeruginosa in mice

In cystic fibrosis, a recessive genetic disease caused by defects in the cystic fibrosis conductance regulator (CFTR), the main cause of death is lung infection and inflammation. Nutritional deficits have been proposed to contribute to the excessive host inflammatory response in both humans and Cftr-knockout mice. Cftr-knockout mice and gut-corrected Cftr-knockout mice expressing human CFTR primarily in the gut were challenged with Pseudomonas aeruginosa-laden agarose beads; they responded similarly with respect to bronchoalveolar lavage cell counts and levels of the acute-phase cytokines tumor necrosis factor alpha, interleukin-1beta (IL-1beta), and IL-6. Wild-type mice fed the liquid diet used to prevent intestinal obstruction in Cftr-knockout mice had inflammatory responses to P. aeruginosa-laden agarose beads similar to those of wild-type mice fed an enriched solid diet, so dietary effects are unlikely to account for differences between wild-type mice and mice with cystic fibrosis. Finally, since cystic fibrosis patients and Cftr-knockout mice have an imbalance in fatty acids (significantly lower-than-normal levels of docosahexaenoic acid), the effects of specific supplementation with docosahexaenoic acid of wild-type and Cftr-knockout mice on their inflammatory responses to P. aeruginosa-laden agarose beads were tested. There were no significant differences (P = 0.35) in cumulative survival rates between Cftr-knockout mice and wild-type mice provided with either the liquid diet Peptamen or Peptamen containing docosahexaenoic acid. In conclusion, diet and docosahexaenoic acid imbalances alone are unlikely to explain the differences in the host response to lung infections with mucoid P. aeruginosa between mice with cystic fibrosis and their wild-type counterparts.