Selection for carcass quality in hill sheep measured by X-ray computer tomography.

This paper describes an investigation of the use of computer tomography (CT) to genetically improve carcass composition and conformation in Scottish Blackface sheep. After 5 years of selection on an index designed to improve both composition and conformation (the 'CT index'), a large response was observed in the CT index, with genetic progress equivalent to 0.11 phenotypic standard deviations per year. Heritabilities for the index and for the component traits of average CT-assessed muscle area, ultrasonic muscle depth and ultrasonic fat depth were 0.41 (s.e. 0.08), 0.38 (s.e. 0.07), 0.41 (s.e. 0.05) and 0.30 (s.e. 0.05), respectively. The index was positively genetically correlated with ultrasonic muscle depth and carcass weight and negatively genetically correlated with fat class. The genetic and phenotypic correlations among ultrasonic measurements were positive and moderate. However, many of the genetic correlations tended to have large standard errors. Selection on the CT index moderately improved conformation and was successful at decreasing fat class of the carcass. Equivalent selection on live weight at ultrasound scanning would improve carcass and slaughter weight, and total price received, but would have a slightly deleterious impact on conformation score. The results of this study demonstrate that genetic improvement of carcass quality can be achieved in hill sheep using CT assessed traits.

Surface plasmon polaritons and their role in the enhanced transmission of light through periodic arrays of subwavelength holes in a metal film.

We present results of the transmitted, reflected, and absorbed power associated with the enhanced transmittance of light through a silver film pierced by a periodic array of subwavelength holes. Comparing experimentally acquired dispersion curves under different polarization conditions shows that the transmission features of the array are consistent with p-polarized resonant modes of the structure. By exploring the regime in which no propagating diffracted orders are allowed, we further show that the transmittance maxima are associated with both reflectance minima and absorption maxima. These new results provide strong experimental evidence for transmission based on diffraction, assisted by the enhanced fields associated with surface plasmon polaritons.

Site 5 air sparging pilot test, Naval Air Station Cecil Field, Jacksonville, Florida.

A 72-h air sparging pilot test was conducted at Site 5 (Operable Unit 2), Naval Air Station Cecil Field, Jacksonville, FL, to determine performance parameters necessary for full-scale design. The sparge well was completed to a depth of 29 ft, several feet below the groundwater plume contaminated with volatile organic compounds (VOCs), primarily benzene, toluene, ethylbenzene, and xylenes (BTEX). Air flow rates supplied to the sparge well were 3 cubic feet/min (cfm) during the first day, 2 cfm during the second day, and 1 cfm during the third day. Water levels in monitoring wells initially rose approximately 2 ft during the first 4-5 h of the test, then receded back to pre-test equilibrium levels over the next 15 h, for a total duration of water mounding of about 20 h. A small (approximately 0.5 ft) water table drop, with subsequent recovery to equilibrium level, occurred each time the air sparging rate was decreased. Although there is considerable variation depending on direction from the sparge well, the average radius of influence varied from approximately 30 ft at 1 cfm to 50 ft at 3 cfm. The air sparge system was capable of increasing the dissolved oxygen from 0 to 6 or 7 mg/l within 12-15 h of air channels reaching a given location. A lag time of approximately 13 h was observed before air channels reached a radius of 30 ft and dissolved oxygen levels began to increase at that radius. CO(2) (stripped out of the groundwater by the sparging) decreased from a pre-test concentration of 150 to 20 mg/l at r=5 ft, and from 150 to 50 mg/l at r=30 ft, within a period of about 24 h. The rate of VOC mass removal during the pilot test was 0.06 lb/day at a sparge rate of 3 cfm, and it appears that air sparging will effect a rapid cleanup of the VOCs in the Site 5 groundwater plume.

Amiodarone for resuscitation after out-of-hospital cardiac arrest due to ventricular fibrillation.

BACKGROUND: Whether antiarrhythmic drugs improve the rate of successful resuscitation after out-of-hospital cardiac arrest has not been determined in randomized clinical trials. METHODS: We conducted a randomized, double-blind, placebo-controlled study of intravenous amiodarone in patients with out-of-hospital cardiac arrest. Patients who had cardiac arrest with ventricular fibrillation (or pulseless ventricular tachycardia) and who had not been resuscitated after receiving three or more precordial shocks were randomly assigned to receive 300 mg of intravenous amiodarone (246 patients) or placebo (258 patients). RESULTS: The treatment groups had similar clinical profiles. There was no significant difference between the amiodarone and placebo groups in the duration of the resuscitation attempt (42+/-16.4 and 43+/-16.3 minutes, respectively), the number of shocks delivered (4+/-3 and 6+/-5), or the proportion of patients who required additional antiarrhythmic drugs after the administration of the study drug (66 percent and 73 percent). More patients in the amiodarone group than in the placebo group had hypotension (59 percent vs. 48 percent, P=0.04) or bradycardia (41 percent vs. 25 percent, P=0.004) after receiving the study drug. Recipients of amiodarone were more likely to survive to be admitted to the hospital (44 percent, vs. 34 percent of the placebo group; P=0.03). The benefit of amiodarone was consistent among all subgroups and at all times of drug administration. The adjusted odds ratio for survival to admission to the hospital in the amiodarone group as compared with the placebo group was 1.6 (95 percent confidence interval, 1.1 to 2.4; P=0.02). The trial did not have sufficient statistical power to detect differences in survival to hospital discharge, which differed only slightly between the two groups. CONCLUSIONS: In patients with out-of-hospital cardiac arrest due to refractory ventricular arrhythmias, treatment with amiodarone resulted in a higher rate of survival to hospital admission. Whether this benefit extends to survival to discharge from the hospital merits further investigation.

Autoradiographic evidence that zona glomerulosa and capsular vessels of the human adrenal cortex are provided with different subtypes of adrenomedullin receptors.

Frozen sections of normal adrenal glands, obtained from patients undergoing unilateral nephrectomy for kidney cancer, were labeled in vitro with human [125I]ADM(1-52). Autoradiography and quantitative densitometry showed the presence of abundant ADM(1-52) binding sites in both zona glomerulosa (ZG) and capsular vessels, which were displaced with about the same efficiency by cold ADM(1-52) and rat ADM(1-50). The selective calcitonin gene-related peptide type 1 (CGRPI) ligand CGRP(8-37) eliminated, although less efficiently than ADMs, [125I]ADM(1-52) binding in the ZG, but not in the capsular vessels. These findings suggest the existence of different receptor subtypes for ADM in the human adrenal cortex. The CGRP(8-37)-sensitive receptors located in the ZG may mediate the well-known inhibitory effect of ADM on aldosterone secretion, while the CGRP(8-37)-insensitive receptors present in the capsular vessel may be involved in the ADM-induced rise in adrenal blood flow.

Long QT syndrome during high-dose cisapride.

The gastrointestinal prokinetic drug, cisapride, is widely used for the treatment of diabetic gastroparesis and disorders of gastrointestinal motility. We present a case of acquired QT prolongation, syncope, and nonsustained ventricular tachycardia associated with high doses of cisapride.

Intracellular localization of lactosylceramide, the major human neutrophil glycosphingolipid.

The abundance of lactosylceramide (LacCer; Gal beta 1-4Glc beta 1-1Cer) in human polymorphonuclear neutrophils (PMN) (about 10(9) molecules/cell) seemed inconsistent with an exclusive plasma membrane LacCer localization in these cells. Therefore, the distribution of LacCer between plasma membrane and intracellular compartments was analyzed. Binding of 125I-labeled monoclonal anti-LacCer antibody (T5A7) to intact cells indicated that only 0.1-0.2% of total LacCer was accessible to antibody. Chemical and immunochemical comparisons of organic extracts prepared from PMN cytoplasts (i.e. PMN depleted of nucleus and granules) and intact PMN demonstrated that less than 25% of PMN LacCer was plasma membrane-derived. Simultaneous particle volume and surface staining analyses suggested that selective LacCer loss from cytoplasts could not explain this result. Intracellular LacCer was demonstrated by intense staining of PMN frozen thin sections with T5A7 in indirect immunofluorescence tests. Two-color fluorescence studies using frozen thin sections of neutrophils previously surface-stained with saturating concentrations of T5A7 indicated that this staining did not reflect section artifact. Organic extracts of density gradient-fractionated PMN cavitates were analyzed by radioimmunoassay to determine whether LacCer associates with known populations of PMN granules. Antigen predominantly cosedimented with enzyme markers for primary and secondary granules rather than with plasma membrane marker. Thin layer chromatography of glycolipids extracted from these density gradient fractions identified LacCer as the only antigenic species and demonstrated that chemically detectable LacCer was primarily in granule-enriched rather than plasma membrane fractions. These data indicate that human PMN LacCer is predominantly intracellular and that the glycolipid may be a constituent of PMN lysosomal granules.

Toxoplasma gondii isolated from amniotic fluid.

A pregnant woman contracted toxoplasmosis from exposure to oocysts shed by cats. She underwent amniocentesis for a therapeutic abortion, and Toxoplasma gondii was isolated from the amniotic fluid and placenta. This method may be useful in determining whether the fetus is infected in cases of toxoplasmosis acquired during pregnancy.

Liquid chromatography in pharmaceutical analysis V: determination of an isoniazid-pyridoxine hydrochloride mixture.

Operating parameters are described for the qualitative and quantitative analysis of an isoniazid-pyridoxine hydrochloride mixture by high-pressure liquid chromatography. Each compound was chromatographed on an octadecyl column, using absolute methanol-water (60:40) (pH 2.5) containing 0.01 M dioctyl sodium sulfosuccinate. The flow rate was 2.0 ml/min (2500 psig), and the peaks were detected at 293 nm. The analysis was accomplished using ion-pair formation for effecting chromatographic separation. The time required for separation of the drug mixture is approximately 12 min with an accuracy of 1.17-0.30%.