Recombinant RNA replicons derived from attenuated Venezuelan equine encephalitis virus protect guinea pigs and mice from Ebola hemorrhagic fever virus.

RNA replicons derived from an attenuated strain of Venezuelan equine encephalitis virus (VEE), an alphavirus, were configured as candidate vaccines for Ebola hemorrhagic fever. The Ebola nucleoprotein (NP) or glycoprotein (GP) genes were introduced into the VEE RNA downstream from the VEE 26S promoter in place of the VEE structural protein genes. The resulting recombinant replicons, expressing the NP or GP genes, were packaged into VEE replicon particles (NP-VRP and GP-VRP, respectively) using a bipartite helper system that provided the VEE structural proteins in trans and prevented the regeneration of replication-competent VEE during packaging. The immunogenicity of NP-VRP and GP-VRP and their ability to protect against lethal Ebola infection were evaluated in BALB/c mice and in two strains of guinea pigs. The GP-VRP alone, or in combination with NP-VRP, protected both strains of guinea pigs and BALB/c mice, while immunization with NP-VRP alone protected BALB/c mice, but neither strain of guinea pig. Passive transfer of sera from VRP-immunized animals did not confer protection against lethal challenge. However, the complete protection achieved with active immunization with VRP, as well as the unique characteristics of the VEE replicon vector, warrant further testing of the safety and efficacy of NP-VRP and GP-VRP in primates as candidate vaccines against Ebola hemorrhagic fever.

Sequence variation within the neuropeptide Y gene and obesity in Mexican Americans.

OBJECTIVE: Recently, we reported evidence for linkage between neuropeptide Y (NPY) and both obesity and several obesity-related quantitative measures in a sample of Mexican Americans from Starr County, Texas. The purpose of this study was to investigate putative variation within the coding and promoter regions of NPY. RESEARCH METHODS AND PROCEDURES: Five young, obese individuals (body mass index [BMI] 33 to 45 kg/m2, age 14 to 30 years); five adult, lean individuals (BMI 20 to 26 kg/m2, age 39 to 65 years); and five sibling pairs sharing no alleles that were identical by descent at a marker locus proximal to NPY were selected for fluorescence-based sequencing of approximately 1100 base pairs (bp) immediately 5' from the start site and all four exons of NPY. We identified a total of eight variant sites, including a 2-bp insertion/deletion (I/D) within a putative negative regulatory region (-880I/D) and a 17-bp deletion at the exon 1/intron 1 junction (69I/D). The -880I/D and 69I/D variants were typed in a separate random sample of Mexican Americans (N = 914) from Starr County, Texas. RESULTS: Analyses of variance resulted in a significant association between -880I/D and waist-to-hip ratio (p = 0.041) in the entire sample and between -880I/D and BMI (p = 0.031), abdominal circumference (p = 0.044), and waist-to-hip ratio (p = 0.041) in a non-obese subsample (BMI < 30 kg/m2, n = 594). The 69I/D variant was observed in only one pedigree and does not appear to segregate with obesity within this pedigree. DISCUSSION: This study reports newly identified common human sequence variation within the regulatory and coding sequence of NPY. Several variants were observed, and of those tested, the -880I/D promoter region variant may influence body fat patterning in non-obese individuals but does not appear to play a major role in the etiology of common forms of obesity in this population.

Cerebral vasoreactivity to arterial carbon dioxide tension in preterm infants: the effect of ibuprofen.

Cerebral vasoreactivity to CO(2), calculated by linear regression of total cerebral hemoglobin, measured by near infrared spectroscopy, and corresponding PaCO(2), in infants <32 weeks' gestation, was found to be unaffected by the administration of ibuprofen, which was given on the first postnatal day as prophylaxis against patent ductus arteriosus.

Linkage analysis of candidate obesity genes among the Mexican-American population of Starr County, Texas.

Recent advances in the molecular basis of body fat regulation have identified several genes in which genetic variation may influence obesity and related measures in human populations. Genes that have been shown to have a regulatory function in the control of body fat utilization, eating behavior, and/or metabolic rate in rodent models of obesity include leptin (LEP), leptin receptor (LEPR), neuropeptide Y (NPY), NPY Y1 receptor (NPYY1), glucagon-like peptide-1 (GLP-1), GLP-1 receptor (GLP1R), and uncoupling protein 1 (UCP1). We have typed microsatellite markers located within or near these seven candidate obesity genes in 302 non-diabetic individuals from 59 Mexican-American families from Starr County, Texas. Sib pair linkage analysis was used to examine linkage between these genes and obesity status (obese siblings only; n = 170 pairs) and several obesity-related quantitative variables (all siblings; n = 545 total sibling pairs). Significant linkage (P = 0.042) was found between obesity and NPY within the obese sibling pairs. No other candidate gene was linked to obesity status in this subsample. Consistent with the obese sib pair linkage results, NPY showed evidence of linkage to body weight (P = 0.020), abdominal circumference (P = 0.031), hip circumference (P = 0.012), diastolic blood pressure (P = 0.005), and a composite measure of body mass and size (P = 0.048) in the entire sibling sample. Other significant linkages observed were between LEP and waist/hip ratio (P = 0.010), total cholesterol (P = 0.030), and HDL cholesterol (P = 0.026) and between LEPR and fasting blood glucose (P = 0.018) and diastolic blood pressure (P = 0.003). These results support further investigation of NPY, LEP, and LEPR to identify genetic variation that may influence obesity status, glucose and lipid metabolism, and blood pressure in Mexican Americans.

Comparative evaluation of the effects of indomethacin and ibuprofen on cerebral perfusion and oxygenation in preterm infants with patent ductus arteriosus.

OBJECTIVE: To compare the effects on cerebral perfusion and oxygenation of intravenous ibuprofen and indomethacin as treatment for patent ductus arteriosus in preterm infants. STUDY DESIGN: Sixteen infants receiving mechanical ventilation (< 31 weeks gestation) with patent ductus arteriosus received either 0.2 mg/kg indomethacin (n = 8) or 10 mg/kg ibuprofen (n = 8) infused over 1 minute. Near-infrared spectroscopy was used to measure changes in cerebral blood volume and in oxidized cytochrome oxidase concentration. Cerebral blood flow velocity in the pericallosal artery was measured using Doppler ultrasonography. RESULTS: Indomethacin caused a significant reduction of CBV (maximal changes in cerebral blood volume: -320 +/- 171 microL/100 gm) and, in four of eight patients, a fall in oxidized cytochrome oxidase concentration (maximal change in oxidized cytochrome oxidase concentration in the eight patients: -0.68 +/- 0.98 mumol/L, NS). Cerebral blood flow velocity fell significantly. Ibuprofen caused no significant reduction of cerebral blood volume, oxidized cytochrome oxidase concentration, or cerebral blood flow velocity, whereas a significant increase of cerebral blood volume (+207 +/- 200 microL/100 gm) was observed after 60 minutes. Ductus closure was seen in six of eight infants after the first dose of indomethacin and in five of eight infants after the first dose of ibuprofen. The therapeutic cycle involved administration of a second and third dose, provided no side effects occurred. Treatment was effective in all infants. CONCLUSION: Compared with indomethacin, treatment with ibuprofen does not significantly reduce cerebral perfusion and oxygen availability; the observed increase in cerebral blood volume requires further investigation.

OB gene not linked to human obesity in Mexican American affected sib pairs from Starr County, Texas.

Obesity is a highly prevalent disease, which is associated with a number of chronic conditions and, as such, represents a major public health burden. Numerous studies indicate that there is a genetic component contributing to interindividual variability in obesity. The discovery of the ob gene in mice, mutations in which produce extreme obesity and non-insulin-dependent diabetes mellitus (NIDDM), provides a prime candidate gene for human obesity. We investigated linkage between the human OB gene and obesity in a sample of Mexican Americans from Starr County, Texas. Markers D7S635 and D7S1875, estimated to lie within a region approximately 290 to 400 kb proximal to the OB gene, were used to genotype 177 obese individuals distributed in 64 sibships. Obesity was defined as a body mass index (BMI) above 30 kg/m2. Linkage analyses for affected sibling pairs provided no evidence for linkage in this sample. In addition, differences between siblings for weight, BMI, systolic and diastolic blood pressure, percent body fat, waist-to-hip ratio, and blood lipid measures were not significantly related to number of alleles shared identical by state (IBS) for either of the two markers. While the OB gene may be involved in the metabolic sequences leading to obesity, the present linkage results do not support the existence of common genetic variation at or near the OB locus that increases risk for human obesity.

The effect of parasitization by Leishmania mexicana mexicana on macrophage function in vitro.

Macrophages infected with amastigotes of Leishmania mexicana mexicana as compared to normal macrophages show decreased migration both randomly and through a 5 microns pore in response to a known chemotaxin, an increased ability to pinocytose and an increased bactericidal ability. Unless very heavily parasitized their ability to phagocytose is unaltered. Parasitized macrophages are unaltered in their ability to secrete extracellularly lysosomal enzymes, prostaglandins and lysozyme in response to known stimuli, or to kill target cells in an antibody dependent cell mediated cytotoxicity assay.