Possible role of an adrenal parasite reservoir in the pathogenesis of chronic Trypanosoma cruzi myocarditis

A non-parametric estimator of the AIDS survival time (after developing AIDS) is computed for the AIDS data set from the US Air Force (USAF). Survival times are unobservable. They are censored by the screening mechanism. The Armstrong Laboratory's Epidemiologic Research Division maintains data on over 954 active duty US Air Force (USAF) individuals who tested positive for human immunodeficiency virus (HIV) antibodies. Many have been clinically evaluated seven times since 1986. The HIV-positive individual is classified in seven stages of the disease complex as time progresses. Exact times of transition from one stage to the next are unknown. It is known that transition occurred between two consecutive evaluations. The aim of this study is to analyse distributions of the times that individuals spend in each stage of the HIV disease complex. We will discuss methods used to obtain non-parametric estimators of the distribution of times that individuals spend in stage 6. Finally, it is hoped to model the median time spent in each stage of the disease. This, along with incidence and separation data, will allow the prediction of the impact of HIV disease on USAF individuals and medical care systems.     

Length distribution of aluminum etch tunnels

A model was derived for the length distribution of aluminum etch tunnels, based on an assumed constant death rate per unit length. Both active and dead tunnels were accounted. The model gives reasonable fits to measured tunnel length distribution data with two adjustable parameters, the death rate per unit length and the number of active tunnels. The death rate parameter has a value of about 2% of tunnels dying per m of growth length for the set of experimental data. The numbers of active and dead tunnels appear to be consistent with other tunnel measurements.     

Patterns of DNA synthesis and mitotic activity during the intermoult of Daphnia

Among insects, the epidermal cell cycle pattern is related to the type of ontogenetic development. In taxa undergoing complete metamorphosis, cells are commonly maintained in the G2 stage of interphase between bouts of cell division. In crustaceans, as in insects exhibiting incomplete metamorphosis, it is believed that cells ordinarily remain in G1 for much of the intermoult, with DNA replication occurring late in the moult cycle followed closely by cell division. The present study reveals a differing pattern of epidermal cell division in two distantly related members of the cladoceran crustacean genus Daphnia. Cell cycle kinetics were examined in the last juvenile instar of each species using DNA content determinations and estimates of mitotic frequency. These analyses confirm that each epidermal cell possessed the diploid DNA amount, completed a single cell cycle, and remained in G1 for the majority of the instar. However, DNA replication occurred shortly after moulting and was followed by intense mitotic activity so that cell proliferation was restricted to a short period soon after ecdysis. Cell densities during the instar increased by approximately 60 and 100% for D. pulex and D. magna, respectively.     

Brief, high-frequency stimulation of the corticomedial amygdala induces a delayed and prolonged increase of aggressiveness in male Syrian golden hamsters.

Brief 200-Hz stimulation of the corticomedial amygdala (CMA) increases the aggressiveness of male Syrian golden hamsters for about 30 min; the effect peaks 10–15 min after stimulation. This effect is sensitive to stimulation amplitude and frequency. Stimulation at the parameters that reduce attack latency increases flank marking but does not affect copulation latency or general activity. Immunocytochemical analysis suggests that stimulation effects may be coupled to c-fos expression and that unilateral stimulation has bilateral effects. CMA stimulation effects appear to mimic part of the time course of behaviorally induced attack priming. The temporal persistence of aggression may result from long-term potentiation-like changes within CMA-related neural circuitry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Goal Programming Approaches to Solving Linear Decision Rule Based Aggregate Production Planning Models

This paper reviews several goal programming extensions to the Linear Decision Rule Formulation of the Aggregate Production Planning Problem, and presents an extension using Polynomial Goal Programming. Employing a well known problem as a point of reference, the solution of the various model formulations is illustrated using commercially available mathematical programming software.     

Synthesis of long chaina,B-alkynoic anda,B-alkynoic acids viaB-keto esters

A general method for the synthesis of long chain α,β-alkynoic acids from β-keto esters is described. The synthesis involves conversion of the β-keto ester to the corresponding pyrazolone, then halogenation and treatment of the resultant 4,4-dihalo product with dilute aqueous alkali to form the α,β-alkynoic acids. Specifically, 2-octynoic, 2-nonynoic and 2-decadecynoic acids were prepared as representative examples. If the β-keto ester has an alkyl group at the α-position, the final product is a mixture ofcis andtrans α-substituted-α,β-unsaturated alkenoic acids, which may be separated by gas-liquid chromatography. Pertinent IR and proton magnetic resonance data are used in characterizing the stereochemistry of products and a possible mechanism for the product forming reactions is presented. Presented in part at the AOCS Meeting, October 1966.     

Optical slicing of human retinal tissue in vivo with the adaptive optics scanning laser ophthalmoscope

We present imaging results in human retinal tissue in vivo that allowed us to determine the axial resolution of the adaptive optics scanning laser ophthalmoscope (AOSLO). The instrument is briefly described, and the imaging results from human subjects are compared with (a) the estimated axial resolution values for a diffraction-limited, double-pass instrument and (b) the measured one for a calibrated diffuse retinal model. The comparison showed that the measured axial resolution, as obtained from optical sectioning of human retinas in vivo, can be as low as 71 microm for a 50 microm confocal pinhole after focusing a 3.5 mm beam with a 100 mm focal-length lens. The axial resolution values typically fall between the predictions from numerical models for diffuse and specular reflectors. This suggests that the reflection from the retinal blood vessel combines diffuse and specular components. This conclusion is supported by the almost universal interpretation that the image of a cylindrical blood vessel exhibits a bright reflection along its apex that is considered specular. The enhanced axial resolution achieved through use of adaptive optics leads to an improvement in the volume resolution of almost 2 orders of magnitude when compared with a conventional scanning laser ophthalmoscope and almost a factor of 3 better than commercially available optical coherence tomographic instruments.     

Chemical reactions involved in the catalytic hydrogenation of oils. II. Identification of some volatile by-products

Gas chromatography of the volatile by-products produced during the catalytic hydrogenation of an autoxidized soybean oil with a peroxide number of 11.2 meq/kg yielded approx 41 peaks. Twenty-one of the gas chromatographic fractions were collected and rechromatographed, and their chemical identity studied with micro-iR and mass spectrophotometry. These volatile by-products, according to peak area of gas chromatogram, showed a predominance of hydrocarbons and alcohols. The fractions which have been identified aren-octane,n-nonane,n-decane,n-heptadecane,n-hexanol,n-heptanol,n-decanol,n-hexanal,n-decanal and 3-nonanone. Among the gas chromatographic fractions collected,n-decanol has an odor most reminiscent of that of catalytic hydrogenation. Supported by a PHS research grant HE-06411 from the National Heart Institute, Public Health Service. Paper of the Journal Series, N.J. Agricultural Exper. Sta., Rutgers, The State University of New Jersey, Dept. of Food Science, New Brunswick.     

The development of indications for the preoperative use of recombinant erythropoietin

OBJECTIVE: To develop indications for the preoperative use of recombinant erythropoietin (rHuEPO) alone and in conjunction with preoperative autologous donation (PAD). DESIGN: A 2-round modified Delphi-consensus process. PARTICIPANTS: Nine physicians representing multiple clinical specialties, practice environments and geographic locations. METHOD: From evidence tables and a literature summary (MEDLINE database from January 1985 to August 1996) provided and using the RAND-UCLA appropriateness method, the physicians developed 264 indications for the preoperative use of rHuEPO by permuting 7 clinical factors (age, history of transfusion or antibody incompatibility, hemoglobin level, anemia of chronic disease, expected blood loss, presence of cardiovascular or cardiopulmonary disease and patient anxiety). These indications were rated on a 9-point appropriateness scale. Median scores and measures of agreement were determined. OUTCOME MEASURES: The significance of cost constraints or cost and blood supply constraints and the impact of each clinical factor on the ratings as judged by statistical analysis. RESULTS: Of the 264 indications, 54% were rated appropriate, 18% uncertain and 28% inappropriate. Expected blood loss had the greatest impact on the ratings (high expected blood loss had a 5.9 point more appropriate rating on the 9-point scale than low expected blood loss [p < 0.0001]). Preoperative hemoglobin level also significantly influenced the ratings (p < 0.0001). Compared with the clinical context, the ratings under the cost constraint were 1.0 less appropriate (p < 0.0001) for rHuEPO alone and 1.2 less appropriate for rHuEPO and PAD (p < 0.0001). The ratings for patients with moderate expected blood loss were significantly influenced by the cost constraint (less appropriate). CONCLUSIONS: Expected blood loss and preoperative hemoglobin level were the best indicators of rHuEPO appropriateness. Different contexts modify the appropriateness ratings of an expensive drug like rHuEPO.     

Effect of nanovesicle-encapsulated nisin on growth of Listeria monocytogenes in milk

Commercial nisin was encapsulated in nanovesicles (mean diameter 140 nm) prepared from partially purified soy lecithin. Nisin-loaded liposomes and unencapsulated (free) nisin were initially tested in BHI medium and skim milk inoculated with Listeria monocytogenes and incubated for 48 h at 30 °C. At such abuse temperature conditions, free nisin showed better inhibitory than the liposomal counterparts. Subsequently, the effect of encapsulated or free nisin was evaluated in combination with refrigeration (7 ± 1 °C) in both whole (3.25% fat) and skim (0% fat) milk for up to 14 day. A decrease of 3–4 log cycles in L. monocytogenes counts was observed for free and encapsulated nisin at 0.5 mg/ml concentration. Liposome encapsulation of antimicrobial peptides may be important to overcome stability issues and interaction with food components. The utilization of nanovesicle-encapsulated nisin in combination with low temperatures appeared to be effective to control L. monocytogenes in milk, emphasizing the importance of hurdle technology to assure food safety.