Comparison of the effects of dietary glucose versus galactose on porcine feto-placental glucose metabolism

The present study was conducted to determine whether dietary galactose can be used to improve glycogen and lipid accretion in fetal pigs. Pregnant gilts were fed diets containing either 24% glucose (control) or 24% galactose from d 98 to 110 of gestation. Gilts underwent abdominohysterotomy on d 110 of gestation. Slices of fetal subcutaneous adipose tissue and placenta were examined for metabolic capacity for glucose and for galactose utilization. No effects of maternal diet were evident upon glycogen content or enzyme activity of fetal semitendinosus muscle and liver. Maternal dietary galactose had no direct effects upon placental glucose oxidation or use for lipid synthesis. However, galactose supplementation of the incubation medium caused reductions in glucose oxidation (15%) and total lipid synthesis (24%) by the maternal placenta. Maternal dietary galactose caused an increase in total lipid (50%) and fatty acid synthesis (200%) from glucose in fetal subcutaneous adipose tissue; direct supplementation of galactose to the incubation medium had no effect on these parameters. The results of the present study suggest that feeding galactose to the pregnant gilt does not have direct effects upon placental metabolism or fetal glycogen storage. However, these data indicate that use of galactose in the maternal diet can result in an increase in the utilization of glucose for lipogenesis by fetal adipose tissue in swine. This effect is not a direct effect of galactose because transport across the placenta was not apparent.

Plague in a neonate

More than half of the cases of plague in the United States are diagnosed in children. In the 1970s, 105 cases were reported, a 350% increase over the 1960s. Plague should be considered in the differential diagnosis of children from the western United States who have sepsis, especially those with lymphadenopathy. Complications of plague include meningitis, metabolic encephalopathy, abscess, and pneumonia. With appropriate treatment, prompt clinical response usually occurs. Careful isolation and epidemiologic investigation are essential to prevent the spread of the disease.

Low-density lipoprotein-related receptor protein 1 (LRP-1) is not required for insulin-like growth factor binding protein 3 (IGFBP-3) to suppress L6 myogenic cell proliferation

Insulin-like growth factor binding protein-3 (IGFBP-3) suppresses proliferation of numerous cell types, including myogenic cells, via both insulin-like growth factor (IGF)-dependent and IGF-independent mechanisms; however, the mechanism of IGF-independent suppression of proliferation is not clearly defined. In nonmuscle cells, binding of IGFBP-3 to the low-density lipoprotein receptor-related protein-1 (LRP-1)/activated α(2)M receptor is reportedly required for IGFBP-3 to inhibit proliferation. These findings suggest that binding to this receptor also may be required for IGFBP-3 to suppress proliferation of cultured myogenic cells. To investigate the role of the LRP-1 receptor in suppression of myogenic cell proliferation by IGFBP-3, we have examined the effect of receptor-associated protein, an LRP-1 receptor antagonist, on recombinant porcine (rp)IGFBP-3 inhibition of L6 myogenic cell proliferation. Treatment with receptor-associated protein results in a 37% decrease (P < 0.05) in the ability of rpIGFBP-3 to inhibit L6-cell proliferation. In L6 cells subjected to LRP-1 small interfering RNA treatment for 48 h (LRP-1 silenced), LRP-1 mRNA levels were reduced by greater than 80% compared with control cultures treated with nonsense small interfering RNA (mock silenced). In addition, the 85-kDa transmembrane subunit of LRP-1 was undetectable in Western immunoblots of total protein lysates from LRP-1-silenced cells. Even though LRP-1 mRNA and protein levels were dramatically reduced in LRP-1-silenced L6 cells compared with mock-silenced controls, rpIGFPB-3 suppressed proliferation rate to the same extent in both LRP-1-silenced and mock-silenced cultures. Our results strongly suggest that, in contrast to data obtained for nonmuscle cell lines, the LRP-1 receptor is not required for IGFBP-3 to suppress proliferation of L6 myogenic cells.