Gender differences in the relationship between leptin, insulin resistance and the autonomic nervous system.

Objectives: Leptin, an important hormonal regulator of body weight, has been shown to stimulate the sympathetic nervous system (SNS) in vitro although the physiological relevance remains unclear. Increased SNS activity has been implicated in the pathogenesis of insulin resistance and an increased cardiovascular risk. We have therefore investigated the relationship between leptin, insulin resistance and cardiac autonomic activity in healthy young adults.

Single wall carbon nanotube amplification: en route to a type-specific growth mechanism.

With the desire to mass produce any specific n,m type of single wall carbon nanotube (SWNT) from a small sample of the same material, we disclose here the preliminary work directed toward that goal. The ultimate protocol would involve taking a single n,m-type nanotube sample, cutting the nanotubes in that sample into many short nanotubes, using each of those short nanotubes as a template for growing much longer nanotubes of the same type, and then repeating the process. The result would be an amplification of the original tube type: a parent SWNT serving as the prolific progenitor of future identical SWNT types.

An outbreak of extrinsic alveolitis at a car engine plant.

Background: Twelve workers from a car engine-manufacturing plant presented with extrinsic allergic alveolitis (EAA), with heterogeneous clinical, radiological and pathological findings. They were exposed to metalworking fluids (MWF) that cooled, lubricated and cleaned the machines.

Methods: They were characterized by history, examination, lung function testing, radiology, bronchoscopic lavage, lung biopsy and serology.

Maternal dietary intake in twin pregnancies: does it diminish towards term?

We tested the hypothesis that energy intake among women with twin pregnancies decreases in late gestation, as the uterus enlarges and they become increasingly uncomfortable. We asked women to recall dietary intake for the previous 24 hours, every 2 weeks from around 29 weeks of gestation, using a photographic atlas and other strategies to estimate portion size. Eighty women provided data at around 29, 31, 33 and 35 weeks of gestation.

High permeability of the anionic form restricts accumulation of indomethacin by cultured gastric surface epithelial cells exposed to low apical pH.

The 'ion-trapping' hypothesis suggests that the intracellular concentration of acidic non-steroidal anti-inflammatory drugs in gastric epithelial cells could be much higher than in the gastric lumen, and that such accumulation could contribute to their gastrotoxicity. Our aim was to examine the effect of the pH of the apical medium on the apical to basal transfer of the acidic drug indomethacin (pKa 4.5) across a gastric mucous epithelial cell monolayer, and to determine whether indomethacin accumulated in cells exposed to a low apical pH.

Mothers' views on feeding infants around the time of weaning.

Objective: To describe women's views about aspects of infants' diets around the time of weaning, making comparisons with national guidelines.

Design: A survey of women with a 9-month-old child.

Setting: Adelaide, South Australia.

Diet around conception and during pregnancy--effects on fetal and neonatal outcomes.

Substrate supply to the fetus is a major regulator of prenatal growth. Maternal nutrition influences the availability of nutrients for transfer to the fetus. Animal experiments demonstrate that restriction of maternal protein or energy intake can retard fetal growth.

A study of the formation, purification and application as a SWNT growth catalyst of the nanocluster [HxPMo12O40[subset]H4Mo72Fe30(O2CMe)15O254(H2O)98].

The synthetic conditions for the isolation of the iron-molybdenum nanocluster FeMoC [HxPMo12O40 [subset]H4Mo72Fe30(O2CMe)15O254(H2O)98], along with its application as a catalyst precursor for VLS growth of SWNTs have been studied. As-prepared FeMoC is contaminated with the Keplerate cage [H4Mo72Fe30(O2CMe)15O254(H2O)98] without the Keggin [HxPMo12O40]n- template, however, isolation of pure FeMoC may be accomplished by Soxhlet extraction with EtOH. The resulting EtOH solvate is consistent with the replacement of the water ligands coordinated to Fe being substituted by EtOH.

Gender differences in the insulin-like growth factor axis response to a glucose load.

Aims: The insulin-like growth factors (IGFs) are thought to contribute to glucose homeostasis. The aim of our study was to examine the response of the IGFs and their binding proteins to an intravenous load of glucose in a cohort of young men and women with normal glucose tolerance.

Methods: The intravenous glucose tolerance test (IVGTT) was used to quantify insulin sensitivity and insulin secretion in 160 adults aged 20-21 years in Adelaide, Australia.

FEV1 decline in occupational asthma.

Background: In occupational asthma continued workplace exposure to the causative agent is associated with a poor prognosis. However, there is little information available on how rapidly lung function declines in those who continue to be exposed, nor how removal from exposure affects lung function.

Methods: Forced expiratory volume in 1 second (FEV1) was studied in 156 consecutive subjects with occupational asthma (87% due to low molecular weight agents) using simple regression analyses to provide estimates of the decline in FEV1 before and after removal from exposure.

Short-term respiratory effects of cleaning exposures in female domestic cleaners.

Symptoms of obstructive lung disease in domestic cleaners have been related to the use of bleach and other irritant cleaning products. The short-term effects of cleaning exposures on respiratory symptoms and peak expiratory flow (PEF) were investigated in domestic cleaners with respiratory disorders. In a panel study, 43 female domestic cleaners with a recent history of asthma and/or chronic bronchitis completed a 2-week diary, collecting information on respiratory symptoms, PEF and cleaning exposures.

Excitons in carbon nanotubes with broken time-reversal symmetry.

Near-infrared magneto-optical spectroscopy of single-walled carbon nanotubes reveals two absorption peaks with an equal strength at high magnetic fields (>55 T). We show that the peak separation is determined by the Aharonov-Bohm phase due to the tube-threading magnetic flux, which breaks the time-reversal symmetry and lifts the valley degeneracy. This field-induced symmetry breaking thus overcomes the Coulomb-induced intervalley mixing which is predicted to make the lowest exciton state optically inactive (or dark).

White-tailed deer (Odocoileus virginianus) develop spirochetemia following experimental infection with Borrelia lonestari.

Borrelia lonestari is considered a putative agent of southern tick-associated rash illness (STARI) and is known to occur naturally only in lone star ticks (Amblyomma americanum) and white-tailed deer (Odocoileus virginianus). We used a low passage isolate of B. lonestari (LS-1) to inoculate white-tailed deer, C3H mice, Holstein cattle, and beagles.

Functionalization density dependence of single-walled carbon nanotubes cytotoxicity in vitro.

The cytotoxic response of cells in culture is dependant on the degree of functionalization of the single-walled carbon nanotube (SWNT). After characterizing a set of water-dispersible SWNTs, we performed in vitro cytotoxicity screens on cultured human dermal fibroblasts (HDF). The SWNT samples used in this exposure include SWNT-phenyl-SO(3)H and SWNT-phenyl-SO(3)Na (six samples with carbon/-phenyl-SO(3)X ratios of 18, 41, and 80), SWNT-phenyl-(COOH)(2) (one sample with carbon/-phenyl-(COOH)(2) ratio of 23), and underivatized SWNT stabilized in 1% Pluronic F108.

A collagen IV matrix is required for guinea pig gastric epithelial cell monolayers to provide an optimal model of the stomach surface for biopharmaceutical screening.

The surface epithelial cells of the stomach represent a major component of the gastric barrier. A cell culture model of the gastric epithelial cell surface would prove useful for biopharmaceutical screening of new chemical entities and dosage forms. Primary cultures of guinea pig gastric mucous epithelial cells were grown on filter inserts (Transwells) for 3 days.

Visualization of individual single-walled carbon nanotubes by fluorescent polymer wrapping.

Manipulating optical properties of single-walled nanotubes (SWNTs) is necessary for the development of nanoscale optical devices and probes for biomedical research. In life sciences it will make possible the direct observation of SWNTs inside living cells using optical microscopes. In the nanotechnology field it will enable the development of nanosensors with fluorescent reporting.

Antibiotic exposure does not influence MRP2 functional expression in Caco-2 cells.

Multidrug resistance-associated protein 2 (MRP2) is associated with active drug efflux and may influence oral bioavailability of common classes of drugs. MRP2 expression demonstrates plasticity. Caco-2 cells, a routine in vitro model for predicting oral bioavailability, are often cultured in media containing antibiotics.

Primary and secondary infection with Ehrlichia chaffeensis in white-tailed deer (Odocoileus virginianus).

White-tailed deer (Odocoileus virginianus) are the principal reservoir host for Ehrlichia chaffeensis, causative agent of human monocytic ehrlichiosis (HME). Because white-tailed deer maintain a long-term infection with E. chaffeensis and because deer can be naturally exposed to multiple strains of E.

A paternally inherited duplication in the Prader-Willi/Angelman syndrome critical region: a case and family study.

The Prader-Willi/Angelman Critical Region (PWACR; Chromosome 15q11-13) is of interest as a potential locus for genes conferring susceptibility to autism spectrum disorders (ASD). This report describes a female proband referred for evaluation of a possible ASD. Genetic analyses indicated that the proband, her father and one of her sisters, carried a paternally derived interstitial duplication involving 15q11-13.

Stability of high-density one-dimensional excitons in carbon nanotubes under high laser excitation.

Through ultrafast pump-probe spectroscopy with intense pump pulses and a wide continuum probe, we show that interband exciton peaks in single-walled carbon nanotubes (SWNTs) are extremely stable under high laser excitations. Estimates of the initial densities of excitons from the excitation conditions, combined with recent theoretical calculations of exciton Bohr radii for SWNTs, suggest that their positions do not change at all even near the Mott density. In addition, we found that the presence of lowest-subband excitons broadens all absorption peaks, including those in the second-subband range, which provides a consistent explanation for the complex spectral dependence of pump-probe signals reported for SWNTs.

Mitochondrial trifunctional protein defects: molecular basis and novel therapeutic approaches.

Mitochondrial trifunctional protein (MTP) is a complex protein that catalyzes the last three steps of long chain fatty acid oxidation. MTP defects have emerged recently as important inborn errors of metabolism because of their clinical implications. These disorders are recessively inherited and display a spectrum of clinical phenotypes in affected children including hepatic dysfunction, cardiomyopathy, neuro-myopathy, and may cause sudden unexpected infant death if undiagnosed and untreated.

Diet during pregnancy, neonatal outcomes and later health.

Renewed interest in nutrition during pregnancy has been generated by the hypothesis that adult disease has origins in early life. Animal experiments clearly show that altering maternal diet before and during pregnancy can induce permanent changes in the offspring's birth size, adult health and lifespan. Among women living in Western societies, cigarette smoking is the most important factor known to reduce fetal growth, followed by low pre-pregnancy weight and low gestational weight gain.

Association between erythropoietin in cord blood of twins and size at birth: does it relate to gestational factors or to factors during labor or delivery?

We hypothesized that cord blood erythropoietin (EPO), a marker of fetal hypoxia, relates to gestational factors and not solely those associated with delivery. We investigated the association between birth weight SD score (SDS) and cord blood EPO in 290 twins (145 pairs), assessing the influence of gestational versus perinatal factors by comparing the association in those who were delivered by elective cesarean (CS) with that in other delivery modes. Blood EPO values were skewed, so geometric means are presented and log EPO values were used in statistical models.