A novel de novo STXBP1 mutation is associated with mitochondrial complex I deficiency and late-onset juvenile-onset parkinsonism.

Mutations in STXBP1 have recently been identified as a cause of infantile epileptic encephalopathy. The underlying mechanism of the disorder remains unclear and, recently, several case reports have described broad and progressive neurological phenotypes in addition to early-onset epilepsy. Herein, we describe a patient with early-onset epilepsy who subsequently developed a progressive neurological phenotype including parkinsonism in her early teens. A de novo mutation in STXBP1 (c.416C>T, p.(Pro139Leu)) was detected with exome sequencing together with profound impairment of complex I of the mitochondrial respiratory chain on muscle biopsy. These findings implicate a secondary impairment of mitochondrial function in the progressive nature of the disease phenotype.

Beef carcasses with larger eye muscle areas, lower ossification scores and improved nutrition have a lower incidence of dark cutting.

This study evaluated the effect of eye muscle area (EMA), ossification, carcass weight, marbling and rib fat depth on the incidence of dark cutting (pH(u)>5.7) using routinely collected Meat Standards Australia (MSA) data. Data was obtained from 204,072 carcasses at a Western Australian processor between 2002 and 2008. Binomial data of pH(u) compliance was analysed using a logit model in a Bayesian framework. Increasing eye muscle area from 40 to 80 cm², increased pH(u) compliance by around 14% (P<0.001) in carcasses less than 350 kg. As carcass weight increased from 150 kg to 220 kg, compliance increased by 13% (P<0.001) and younger cattle with lower ossification were also 7% more compliant (P<0.001). As rib fat depth increased from 0 to 20mm, pH(u) compliance increased by around 10% (P<0.001) yet marbling had no effect on dark cutting. Increasing musculature and growth combined with good nutrition will minimise dark cutting beef in Australia.

Effects of birth weight and postnatal nutrition on neonatal sheep: III. Regulation of energy metabolism.

This study investigated effects of birth weight and postnatal nutrition on regulation of energy metabolism in the neonatal lamb. Low (mean +/- SD 2.289 +/- 0.341 kg, n = 28) and high (4.840 +/- 0.446 kg, n = 20) birth weight male Suffolk x (Finnsheep x Dorset) lambs were individually reared on a liquid diet to grow rapidly (ad libitum fed, ADG = 337 g, n = 20) or slowly (ADG = 150 g, n = 20) from birth to live weights (LW) up to approximately 20 kg. At birth, small newborns had higher plasma concentrations of urea nitrogen (mean +/- SEM 8.31 +/- 0.25 vs 6.39 +/- 0.32 mM, P = 0.002) and somatotropin (ST, 49.1 +/- 17.0 vs 10.8 +/- 4.3 ng/mL, P = .045) and lower IGF-I (36.1 +/- 6.8 vs 157.7 +/- 21.8 ng/mL, P < 0.001) than large newborns. Plasma glucose (1.42 +/- 0.23 vs 2.63 +/- 0.95 mM, P = 0.147) and insulin (0.09 +/- 0.02 vs 0.13 +/- 0.06 ng/mL, P = 0.264) concentrations did not differ. Urea nitrogen concentration in plasma peaked and then declined rapidly in all lambs during the first week postpartum, and plasma ST declined on a body-weight-related basis from birth. During rearing to 20 kg LW, plasma insulin was higher in low- vs high-birth-weight lambs. Lambs fed ad libitum had greater plasma concentrations of glucose, urea nitrogen, insulin, and IGF-I compared to those fed a restricted diet (ADG = 150 g). The results suggest that during the early postpartum period, newborn lambs exhibit the fetal characteristic of high rates of amino acid oxidation. The results also support the notion that, at birth, low-birth-weight lambs are less mature than high-birth-weight lambs in aspects of metabolic and endocrine development, which may enhance their capacity to utilize amino acids for energy production and to support gluconeogenesis during the immediate postpartum period. Being small at birth also resulted in elevated plasma insulin concentrations when adequate nutriment to support moderate or rapid growth was provided postpartum, although it remains to be elucidated whether this more chronic effect persists in the longer term.

Australian farm work injuries: incidence, diversity and personal risk factors.

Information on farm work-related injuries was sought to assist in the design of effective farm safety prevention programs. A telephone survey was conducted using a stratified random sample of 919 sheep/wool, beef cattle and dryland broadacre cropping farms from three shires in the wheat/sheep belt of New South Wales. The adjusted response rate was 84%. There were 425 reported injuries over an 18-month period. One in five farms reported at least one injury per year, while one in 12 farms reported at least one serious injury per year. Animal-related injuries were the largest major category for agent of injury, while the largest category for nature of injury was sprain and strain, recording almost one-quarter of all injuries. The farm workshop or shed was the most common location of injury, with more than 20% of all reported injuries occurring there. Personal risk factors thought to contribute to these farm work-related injuries were examined. The statistically significant personal risk factors for injury occurrence were age (and/or experience), previous injury status, body mass index, hours of sleep, a variable measuring daytime drowsiness and a variable measuring perceived stress.

Short-wavelength light reduces circadian elevation of intraocular pressure in rabbits.

In light-dark entrained rabbits, the intraocular pressure (IOP) increases around the onset of dark due to the increased activities of ocular sympathetic nerves. This circadian elevation of IOP can be eliminated by exposing the rabbits to constant white light in the early subjective dark phase. The spectral effectiveness of light causing the reduction in IOP was studied using lights selectively filtered through various optic filters. Light which passed through a long-pass filter, with a cut-on wavelength at 570 nm or 530 nm, caused no change of the circadian IOP elevation. A significant reduction of the IOP elevation was observed with filtered light via the 495 nm long-pass filter and, to a larger extent, with light via the 475 nm long-pass filter. Short-wavelength light (380-480 nm, peak at 432 nm) passed through a band-pass filter completely eliminated the circadian IOP elevation. The aqueous humor concentration of norepinephrine (NE) under the short-wavelength light was significantly lower than the NE concentration under the filtered light via the 530 nm long-pass filter. Sensation of the short-wavelength light plays an important role in synchronizing the circadian elevation of IOP in rabbits.

Plasma antioxidants and risk of cortical and nuclear cataract.

We evaluated nutritional risk factors for cataract in 660 subjects enrolled in the Baltimore Longitudinal Study on Aging. As a part of a regular cycle of visits, nuclear and cortical lens photographs were taken over a 2-year period. Measurements of plasma antioxidants (beta-carotene, ascorbic acid, and alpha-tocopherol) were obtained in this cohort as part of the study protocol up to 4 years before lens photographs were taken. We found that plasma beta-carotene and ascorbic acid levels were not associated with risk of nuclear or cortical lens opacities. Higher levels of plasma alpha-tocopherol, however, were associated with a reduced risk of nuclear opacity [odds ratio (OR) for highest quartile vs lowest quartile = 0.52, 95% confidence interval (CI) = 0.27-0.98; OR for middle two quartiles vs lowest quartile = 0.55, 95% CI = 0.30-0.98], after adjusting for age, sex, and history of diabetes. Middle levels of alpha-tocopherol were associated with a reduced risk of cortical opacity (OR = 0.57, 95% CI = 0.32-1.02), but no such association was observed for high levels of alpha-tocopherol. We constructed an index of overall antioxidant status, which indicated that higher levels of plasma antioxidants were not associated with risk of nuclear or cortical opacities.

A comparison of medicated and nonmedicated attention-deficit disordered hyperactive boys.

Sixty boys diagnosed as having attention-deficit disorder with hyperactivity were divided into two equal groups, depending on whether or not they were taking medication for their disorder. These two groups were subdivided equally into younger and older groups, the cutoff being 11.5 years. All subjects were given the Children's Depression Inventory, the Coopersmith Self Esteem Inventory and the Children's Attributional Style Questionnaire. Teachers completed the Child Behaviour Checklist and Conners' Teacher Rating Scale. The results indicated that in the older subjects, the medicated group had lower social self-esteem than the nonmedicated group and in younger subjects the medicated group had higher academic self-esteem than the nonmedicated group. There were no significant differences among the groups with respect to depression; all four groups of subjects were mildly depressed. The younger subjects in general were more inattentive, nervous, impulsive and aggressive; and teachers did not report any less externalising behaviour in those subjects who were on medication. These results were interpreted in the light of findings from previous studies, and the lack of drug effect on externalising behaviour is discussed. Clinical recommendations are made for alleviating depression and improving self-concept by means of cognitive therapy, especially for older medicated ADDH children.

Detoxification enzymes following intrastriatal kainic acid.

A complete explanation of the neurotoxicity that follows kainic acid (KA) injection into the rat striatum is lacking. An assessment of the chronological course after intrastriatal KA injection of the activities of enzymes preferentially concentrated in glia or involved in the detoxification of oxygen metabolites is accomplished. An enhancement of the specific activities of glutathione peroxidase (GP) and catalase is found without an alteration in the specific activity of superoxide dismutase (SOD). There is no increase in the in vivo striatal levels of malondialdehyde, a putative indicator of lipid peroxidation, the expected result of cell membrane damage from oxygen metabolites. Understanding the mechanism and importance of the preferential induction of the activities of the detoxification enzymes will require further study.

Effect of aminophyllin and dexamethasone on secretion of pulmonary surfactant in fetal rabbits.

Aminophyllin, dexamethasone, or saline was injected into 27.5-day fetal rabbits 2.5 hr before sacrifice, after which static pressure-volume curves with air were performed. In further similar experiments the lungs were lavaged with physiologic saline which was analysed for total phospholipid content. There were no changes in total lung capacity (TLC) induced with either aminophyllin or dexamethasone. The lungs of fetal rabbits injected with saline retained 44% TLC (+/-3 SE) after deflation to 10 cm H2O trans-pulmonary pressure compared with 48% TLC (+/-3 SE) in those injected with dexamethasone, a difference which was not statistically significant. In contrast, the lungs of fetal rabbits injected with aminophyllin retained 53% TLC (+/-2 SE) after deflation to 10 cm H2O pressure, a significant increase when compared with saline controls (P less than 0.01). There were no changes in lung weight or lung water. These results were interpreted to mean that aminophyllin decreased surface tension and augmented secretion of pulmonary surfactant. This was supported by finding significantly increased total phospholipid recovered in the lung lavage fluid of fetal rabbits injected with aminophyllin, 62 microgram/g dry lung weight (+/-6 SE) compared with 32 microgram/g dry lung weight (+/-3 SE) in saline controls (P less than 0.05). Phospholipid recovered from dexamethasone-injected fetal rabbits was not significantly increased, 38 microgram/g dry lung weight (+/-4 SE).