Search Results - (Author, Cooperation:H. Dhillon)

2016-02-27

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Anaerobiosis ; Animals ; Antimycin A/analogs & derivatives/pharmacology ; Bacterial Proteins ; Biomarkers/blood ; Body Temperature ; Body Weight ; Disease Models, Animal ; Electron Transport/drug effects ; Electron Transport Complex I/genetics ; Endonucleases ; Energy Metabolism/drug effects/genetics ; Gene Knockout Techniques ; Genome-Wide Association Study ; Glycine/analogs & derivatives/pharmacology/therapeutic use ; Humans ; Hypoxia-Inducible Factor 1/metabolism ; Isoquinolines/pharmacology/therapeutic use ; K562 Cells ; Leigh Disease/*genetics/pathology/*therapy ; Mice ; Mice, Knockout ; Mitochondria/drug effects/*metabolism ; Oxygen/*metabolism ; Respiration ; Suppression, Genetic ; Von Hippel-Lindau Tumor Suppressor Protein/antagonists & inhibitors/*genetics ; Zebrafish

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: Regional levels of lactate and inositol 1,4,5-trisphosphate (IP3), a cellular second messenger of the excitatory neurotransmitter system, were measured after lateral fluid percussion (FP) brain injury in rats. At 5 min postinjury, tissue lactate concentrations were significantly elevated in the cortices and hippocampi of both the ipsilateral and contralateral hemispheres. By 20 min postinjury, lactate concentrations were elevated only in the cortices and hippocampus of the ipsilateral hemisphere. Whereas the IP3 concentrations were elevated in the hippocampi of the ipsilateral and contralateral hemisphere and in the cortex of ipsilateral hemisphere at 5 min postinjury, no elevation in these sites was found at 20 min postinjury. Histologic analysis revealed neuronal damage in the cortex and CA3 regions of hippocampus ipsilateral to the injury at 24 h postinjury. The present results suggest activation of the phosphoinositide signal transduction pathway at the onset of injury and of a possible requirement of early persistent metabolic dysfunction (〉20 min) such as the lactate accumulation in the delayed neuronal damage.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Ciliary neurotrophic factor (CNTF), a cytokine of the interleukin-6 superfamily, has been shown to induce hypophagia and weight loss. Neuropeptide Y (NPY) and orexin are potent orexigenic signals in the hypothalamus. Anorexia, normally seen in response to infection, injury and inflammation, may result from diminished hypothalamic orexigenic signalling caused by persistently elevated cytokines, including CNTF. To test this hypothesis, we first examined the effects of chronic intracerebroventricular (i.c.v.) infusion of CNTF for 6–7 days on food intake and body weight as well as hypothalamic NPY and orexin gene expression in male rats. Subsequently, the effectiveness of NPY replacement to counteract the effects of CNTF by coinfusion of NPY and CNTF was evaluated. Chronic i.c.v. infusion of CNTF (2.5 µg/day) reduced body weight (14.3% vs control) at the end of 7 days. Food intake remained suppressed for 5 days postinfusion and subsequently gradually returned to the control range by day 7. Serum leptin concentrations in these rats were in the same range seen in control rats. Chronic i.c.v. infusion of higher doses of CNTF (5.0 µg/day) produced sustained anorexia and body weight loss (29% vs controls) through the entire duration of the experiment. This severe anorexia was accompanied by markedly suppressed serum leptin concentrations. Furthermore, CNTF infusion alone significantly reduced hypothalamic NPY gene expression (P 〈 0.05) without affecting orexin gene expression. As expected, in fusion of NPY alone (18 µg/day) augmented food intake (191.6% over the initial control, P 〈 0.05) and produced a 25.1% weight gain in conjunction with a 10-fold increase in serum leptin concentrations at the end of the 7-day period. Interestingly, coinfusion of this regimen of NPY with the highly effective anorectic and body reducing effects of CNTF (5.0 µg/day) not only prevented the CNTF-induced anorexia and weight loss, but also normalized serum leptin concentrations and hypothalamic NPY gene expression. These results demonstrate that chronic central infusion to produce a persistent elevation of the cytokine at pathophysiological levels (a situation that may normally manifest during infection, injury and inflammation) produced severe anorexia and weight loss in conjunction with reduction in both serum leptin concentrations and hypothalamic NPY gene expression. Reinstatement of hypothalamic NPY signalling by coinfusion of NPY counteracted these CNTF-induced responses.

Electronic Resource

1432-1998

Springer Online Journal Archives 1860-2000

Medicine

Abstract Seventy children with an antenatal diagnosis of unilateral renal pelvic dilatation underwent Tc 99 m DTPA diuretic renograms. There were 16 kidneys with moderate function, and 54 with good function, 31 underwent pyeloplasty, all had a renal pelvis 〉12 mm diameter on ultrasound. Thirty nine children with good function were treated conservatively. Long term follow up has demonstrated that conservative management for PUJ dilatation with a good functioning kidney may be justified but a randomised control study is required.

Electronic Resource

1435-1536

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Summary Amorphous (and partly micro-crystalline) aluminium hydroxide precipitates were prepared by controlled hydrolysis of aluminium isopropoxide and aluminium sulphate solutions: the kinetics of their dissolution in well-stirred sodium hydroxide solutions (0.25 to 3 g ion/l) in large excess was studied at 5° to 35°C. The reaction is chemically rate-controlled in dilute hydroxide solution. The dissolution of the non-aggregated 30–40 per cent (amorphous) material follows a four-third order mechanism with respect to powder weight; the aggregated material reacts far less rapidly. The rate constants for initial dissolution vary linearly with mean ionic activity of the hydroxide solution. The mechanism of dissolution is similar to that of the dissolution of crystalline boehmite; for this reaction, the rate-controlling step is a reaction between reactive AlOOH sites on the powder surface and hydroxyl ions adsorbed near these sites. For the dissolution of the most amorphous (unaggregated) material,k w1(ata ±=1) at 5°C=6.0g−1/3hr−1,k w 1 at 20°C=22.4 g−1/3hr−1.E act=14.500 cal/mole. Micro-crystalline material reacts at one-third to one-half the above rates andE act=16.000–17.000 cal/mole.

Electronic Resource

1435-1536

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Zusammenfassung Aluminiumhydroxydgele werden in Lösungen höher pH 2 bis 1000 Std. rekristallisiert und ergeben dabei eine Reihe von Gibbsit-PulverP11/2,P11/8,P11/48,P11/360 undP11/X. Sie bestehen aus hexagonalen plättchen-förmigen Kristallen. Die mittlere Dimension (l 0) waren 0,03; 0,06; 0,13; 0,26 und 0,45 microns. Die Auflösung von verdünnten Suspensionen dieser Pulver wurden in stark gerührten Natriumhydroxyd-Lösungen bei 20 bis 65°C untersucht. Das feste Reaktionsprodukt und die Lösung wurden nach verschiedenen Zeiten mit chemischen und physikalischen Methoden analysiert. Die Reaktion erfolgte durch zwei-dimensionale Auflösung der Blättchen. Die Reaktion von GibbsitP11/X (präpariert durch eine auf 1000 Std. verlängerte Kristallisation) waren von 1. Ordnung hinsichtlich Pulver-gewicht, und von 2. Ordnung hinsichtlich effektiver Oberfläche. Die Reaktion der anderen Gibbsite waren von 1. Ordnung für die ersten 20% schnelle Lösung und wurden dann langsamer. Die anfänglichen Reaktionskonstanten und Halbzeiten der Auflösung für alle Gibbsite in Natriumhydroxyd-Lösungen der Ionenstärke 1 waren 1,70; 0,9, 0,60; 2,2; 0,22; 5,5; 0,07; 14 und 0,02, 38. Zahlen in der ReihenfolgeP11/2 bisP11/X. Die Geschwindigkeitskonstanten wachsen linear mit der mittleren Ionenaktivität der Hydroxylödung und wachsen exponentiell mit der reziproken absoluten Temperatur auf das Vier- oder Fünffache für 15°C Temperaturanstieg. Die Halblebensdauern nehmen in analoger Weise ab. Die Aktivierungsenergien variieren zwischen 76 und 83 kJ/mol. Die Geschwindigkeiten der Auflösungen. werden durch die Geschwindigkeit der chemischen Reaktion bestimmt. Zwischen den adsorbierten Hydroxyd-Ionen und den anhaftenden reaktiven Aluminiumhydroxydplätzen an der Kristall-Pulver-Oberfläche.

Summary Aluminium hydroxide gels were recrystallised in high pH solution for 2–1000 h to give a series of Gibbsite powdersP11/2,P11/8,P1/48,P11/360 andP11/X, consisting of hexagonal platelet crystals; their average platelet lengths (l 0) were 0.03, 0.06, 0.13, 0.26 and 0.45 microns. The dissolution of dilute suspensions of these powders in well-stirred sodium hydroxide solutions were studied at 20–65°C Reaction solid and solution were analysed after different times by chemical and physical methods. Reaction occurred by two-directional dissolution of the platelet crystals. The reactions of GibbsiteP11/X (prepared by prolonged 1000 h crystallisation) were first order w.r.t. powder weight (and second order w.r.t. powder effective surface area); the reactions of the other Gibbsites were first order for the first twenty percent rapid dissolution and then slower. The initial rate constantsk w1 (h−1) and half-lifest 0.5 (h) for reactions ofP11/2,P11/8,P11/48.P11/360 andP11/X with sodium hydroxide solution of unit mean ionic activity at 20°C were 1.70, 0.9; 0.60, 2.2; 0.22, 5.5; 0.07, 14 and 0.02, 38 respectively. Rate constants increased linearly with the mean ionic activity of the hydroxide solution and increased exponentially with reciprocal absolute temperature, four to five times for 15°C temperature rise. Half-lifes decreased in a similar manner. Energies of activation varied from 76–83 kJ/mol. The rates of dissolution are determined by the rate of the chemical reaction between adsorbed hydroxyl ions and adjacent reactive aluminium hydroxide sites on the powder crystal surface.

Electronic Resource