Resolvability theory for the multiple-access channel

We study the randomness needed for approximating the output distribution of a multiple-access channel, where the original input processes are independent of each other. The approximation is achieved by simulating (possibly alternative) input processes at each of the entries, where the sources of randomness available for the simulators are independent of each other, and the simulators do not cooperate. The resolvability region of a multiple-access channel is defined as the set of all random-bit rate pairs at which accurate output approximation is possible, where the simulation accuracy is measured by the variational distance between finite-dimensional output distributions. Inner and outer bounds on the resolvability region are derived, and close relations between the concepts of resolvability region and capacity region are demonstrated     

VRCTC-310--a novel compound of purified animal toxins separates antitumor efficacy from neurotoxicity

Two purified animal venom toxins, crotoxin and cardiotoxin, have been combined to produce a unique natural product (VRCTC-310) currently under investigation as an antitumor agent by the National Cancer Institute. In vitro, it has demonstrated cytotoxic disease specificity and a unique mechanism of action when submitted to COMPARE analysis. In vivo, tolerance was developed to the neurotoxic properties of crotoxin which allowed comparison of several schedules of fixed and escalating daily i.m. doses to mice bearing s.c. Lewis Lung carcinoma. An 83% inhibition of tumor growth was achieved using an escalating dose schedule starting at 1.8 mg/kg and reaching 6.3 mg/kg/day on day 20. Although some irritation around the sites of i.m. injection was noted, animal weight loss was negligible and there were no other signs of adverse toxicity. This natural product represents a new, membrane interactive anticancer agent which produces a unique spectrum of cytotoxicity in vitro and which has demonstrated interesting in vivo antitumor efficacy.     

Real-time X-ray diffraction study at different scan rates of phase transitions for dipalmitoylphosphatidylcholine in KSCN

A questionnaire survey was carried out to examine the attitudes and practices of Australian and New Zealand intensivists with regard to brain death and organ donation. A return rate of 82.5% was achieved. Fifty-eight per cent had written evidence of their own wishes to donate organs and 94% would agree to donation from a dependent. At least one intensivist is involved in certifying brain death on 95% of occasions. Intensivists are involved in the request for organ donation over 90% of the time although one-third do not believe that it is their role to request organ donation. Although two-thirds believe that the family should always be approached for organ donation, another 52 out of 254 indicated that it was their (the intensivist's) role to decide if families should be asked for organ donation. Possible reasons for not requesting are language or other communication problems, perceptions of cultural differences and degrees of family distress. Twenty per cent of respondents do not provide haemodynamic support before brain death confirmation. Australian and New Zealand intensivists overwhelmingly support the concept of brain death, current methods of confirmation of brain death, organ donation and transplantation. Possible reasons behind loss of potential donors include decisions not to resuscitate both before and after brain death is confirmed. Perceptions of family grief and cultural differences clearly inhibit requests for organ donation. A very few units have an effective policy on approaching families about organ donation. Intensivists have almost exclusive control over requests for organ donation and thus bear a full professional responsibility for this element of hospital practice.     

Prevalence of gastrointestinal symptoms in obese and normal weight binge eaters

OBJECTIVES: Disturbances in gastrointestinal function may result from disordered eating and may lead to increases in gastrointestinal (GI) symptoms. We compared GI symptoms in obese and non-obese binge eaters and non-binge eaters. METHODS: One hundred nineteen obese and 77 normal-weight females completed a questionnaire on bowel symptoms and binge eating behaviors for the previous 3 months. Based on binge behaviors and body mass index (> 30 kg/m2), individuals were grouped as obese binge eaters (n = 73), obese non-binge eaters (n = 43), non-obese binge eaters (n = 14), and normal-weight controls (n = 61). RESULTS: Obese binge eaters reported more upper GI symptoms than normal controls or obese non-binge eaters (p < 0.001). Compared with normal controls, nausea, vomiting, and bloating was 2-4 times more prevalent in both binge eating groups. Indigestion was more prevalent in both obese groups. Obese binge eaters reported more lower GI symptoms than normal-weight controls (p < 0.05). Binge eating in both weight groups was associated with more frequent abdominal pain and dyschezia. Obesity was associated with more frequent constipation, diarrhea, straining, and flatus, whether or not subjects reported binge eating. Chi-square showed a significant association between obesity, binge eating, and symptoms of irritable bowel syndrome, using the Manning criteria. CONCLUSIONS: Specific GI symptoms were associated with binge eating and obesity. Overall, symptoms were more prevalent and more severe in obese binge eaters. The high prevalence of GI symptoms in obese patients who indulge in binge eating should be considered in their evaluation and treatment.     

Nitrone spin-traps block calcium channels and induce pulmonary artery relaxation independent of free radicals

Free radicals react with nitrones to form stable nitroxides which can be identified by ESR spectroscopy. Unfortunately, little is known regarding the pharmacological properties of these compounds. In this study, three commonly used nitrones, 5,5-dimethylpyrroline-N-oxide (DMPO), alpha-phenyl-tert-butylnitrone (PBN), and alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone (POBN), were found to induce relaxation of preconstricted isolated rat pulmonary artery rings. Additional experiments with PBN indicated that vasorelaxation could not be attributed to production of endothelial derived factors, prostaglandins, or free radicals. Patch-clamp techniques revealed reversible calcium channel blockade with PBN at a concentration below that needed to detect free radicals. Calcium channel blockade probably accounts for the vasorelaxation observed in the isolated ring preparations described here, and should be considered when using nitrone spin-traps both in in vivo and clinical studies.     

Diagnostic neuroimaging: computed tomography and magnetic resonance imaging

BACKGROUND: Computed tomography (CT) and magnetic resonance imaging (MR) are commonly used neuroimaging modalities for patients with signs or symptoms of neuro-ophthalmic disorders. Understanding the technology and clinical uses of these modalities is vital in patient management. METHODS/RESULTS: Basic instrument design and technology are presented together with a discussion of indications and contraindications to the use of these imaging techniques. Case reports are presented to illustrate the usefulness in diagnosis of orbital and neuro-ophthalmic disease. CONCLUSIONS: A basic knowledge of CT and MR helps the optometrist correlate imaging with clinical signs and symptoms of disease. This understanding also results in more effective communication with other health care providers and patients.     

Giant cell myocarditis. Report of a case

The authors report a case of giant cell myocarditis leading to rapidly progressive cardiac failure despite immuno-suppressor treatment in a 20 year old woman. The cardiac failure was successfully managed by implantation of a left ventricular assist device and then cardiac transplantation. The problems encountered underline the importance of accurate diagnosis by endomyocardial biopsy before undertaking treatment and the difficulties in the choice of appropriate method of assistance in this indication. Giant cell myocarditis is a rare cause of cardiac failure and should be considered in the differential diagnosis in view of its clinical features and risk of progression. The literature and the therapeutic implications are discussed.     

Effects of growth hormone-releasing factor and(or) thyrotropin-releasing hormone on growth, feed efficiency, carcass characteristics, and blood hormones and metabolites in beef heifers

The objective of this study was to determine the effect of long-term administration of a growth hormone (GH)-releasing factor analog (GRFa) and(or) thyrotropin-releasing hormone (TRH) on growth, feed efficiency, carcass characteristics, and blood hormones and metabolites in beef heifers. Crossbred heifers (n = 48; 345.9 +/- 2.8 kg) were divided into four equal groups: control (vehicle), 1 microgram of GRFa (human GRF 1-29 analog).kg BW-1.d-1, 1 microgram of TRH.kg BW-1.d-1, or GRFa + TRH. Daily s.c. injections continued for 86 d. Blood samples were collected from half of the heifers after injection on d 1, 36, and 78. On d 89, all heifers were slaughtered. Treatments did not affect (P > .05) ADG but GRFa + TRH decreased (P < .05) ADFI relative to all other treatments. Feed conversion efficiency tended (P < .10) to be improved in the groups given GRFa alone or TRH alone. Treatment with GRFa and(or) TRH did not affect carcass weight, dressing percentage, conformation score, backfat thickness, or weights of liver, kidneys, pituitary, and ovaries. The GRFa + TRH treatment reduced (P < .05) fat score and increased (P < .05) longissimus muscle area relative to other treatments. The GRFa treatments reduced (P < .05) the weight and fat percentage of the mammary gland and increased (P < .05) heart weight. Treatment with TRH alone failed to stimulate GH on d 1, 36, and 78. Treatment with GRFa alone increased (P < .05) GH above controls on d 36, whereas GRFa + TRH increased (P < .05) GH on d 1, 36, and 78. Treatment with GRFa alone increased (P < .05) IGF-I only on d 1, whereas GRFa + TRH was without effect on all days. Across sampling days, treatments had little effect on blood concentrations of insulin, triiodothyronine, nonesterified fatty acids, urea nitrogen, and glucose. The GRFa alone and GRFa + TRH decreased (P < .05) and TRH alone increased (P < .05) thyroxine concentrations. In conclusion, with the dose and administration regimen used, GRFa and(or) TRH yielded small but positive improvements in animal performance.