The asymmetry of antimatter in the proton.

The fundamental building blocks of the proton-quarks and gluons-have been known for decades. However, we still have an incomplete theoretical and experimental understanding of how these particles and their dynamics give rise to the quantum bound state of the proton and its physical properties, such as its spin1. The two up quarks and the single down quark that comprise the proton in the simplest picture account only for a few per cent of the proton mass, the bulk of which is in the form of quark kinetic and potential energy and gluon energy from the strong force2. An essential feature of this force, as described by quantum chromodynamics, is its ability to create matter-antimatter quark pairs inside the proton that exist only for a very short time. Their fleeting existence makes the antimatter quarks within protons difficult to study, but their existence is discernible in reactions in which a matter-antimatter quark pair annihilates. In this picture of quark-antiquark creation by the strong force, the probability distributions as a function of momentum for the presence of up and down antimatter quarks should be nearly identical, given that their masses are very similar and small compared to the mass of the proton3. Here we provide evidence from muon pair production measurements that these distributions are considerably different, with more abundant down antimatter quarks than up antimatter quarks over a wide range of momenta. These results are expected to revive interest in several proposed mechanisms for the origin of this antimatter asymmetry in the proton that had been disfavoured by previous results4, and point to future measurements that can distinguish between these mechanisms.

Fatty acid oxidation products ('green odour') released from perennial ryegrass following biotic and abiotic stress, potentially have antimicrobial properties against the rumen microbiota resulting in decreased biohydrogenation.

AIMS: In this experiment, we investigated the effect of 'green odour' products typical of those released from fresh forage postabiotic and biotic stresses on the rumen microbiota and lipid metabolism. METHODS AND RESULTS: Hydroperoxyoctadecatrienoic acid (HP), a combination of salicylic and jasmonic acid (T), and a combination of both (HPT) were incubated in vitro in the presence of freeze-dried ground silage and rumen fluid, under rumen-like conditions. 16S rRNA (16S cDNA) HaeIII-based terminal restriction fragment length polymorphism-based (T-RFLP) dendrograms, canonical analysis of principal coordinates graphs, peak number and Shanon-Weiner diversity indices show that HP, T and HPT likely had antimicrobial effects on the microbiota compared to control incubations. Following 6 h of in vitro incubation, 15.3% of 18:3n-3 and 4.4% of 18:2n-6 was biohydrogenated in control incubations, compared with 1.3, 9.4 and 8.3% of 18:3n-3 for HP, T and HPT treatments, respectively, with negligible 18:2n-6 biohydrogenation seen. T-RFLP peaks lost due to application of HP, T and HPT likely belonged to as yet uncultured bacteria within numerous genera. CONCLUSIONS: Hydroperoxyoctadecatrienoic acid, T and HPT released due to plant stress potentially have an antimicrobial effect on the rumen microbiota, which may explain the decreased biohydrogenation in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: These data suggest that these volatile chemicals may be responsible for the higher summer n-3 content of bovine milk.

Ruminal protozoal contribution to the duodenal flow of fatty acids following feeding of steers on forages differing in chloroplast content.

Ruminant products are criticised for their SFA content relative to PUFA, although n-6:n-3 PUFA is desirable for human health ( < 4). Rumen protozoa are rich in unsaturated fatty acids due to engulfment of PUFA-rich chloroplasts. Increasing the chloroplast content of rumen protozoa offers a potentially novel approach to enhance PUFA flow to the duodenum and subsequent incorporation into meat and milk. We evaluated protozoal contribution to duodenal n-3 PUFA flow due to intracellular chloroplast content. A total of six Holstein × Friesian steers were fed, in a two-period changeover design, either straw:concentrate (S:C, 60:40; DM basis; S:C, low chloroplast) or fresh perennial ryegrass (PRG; high chloroplast). Following 12 d adaptation to diet, ruminal protozoal and whole duodenal samples were obtained. N and fatty acid content of whole duodenum and rumen protozoal samples were assessed and protozoal 18S rDNA quantitative PCR performed, enabling calculation of protozoal N flow. The ratio of individual fatty acids:N in rumen protozoal samples was calculated to obtain protozoal fatty acid flows. Based on total fatty acid flow, contribution (%) of protozoa to individual fatty acid flows was calculated. Protozoal fatty acid data and microscopical observations revealed that protozoa were enriched with 18 : 3n-3 following PRG feeding, compared with the S:C diet, due to increased intracellular chloroplast content. However, duodenal protozoal 18S rDNA concentration post PRG feeding was low, indicating rumen retention of the protozoa. Nutrition influences the 18 : 3n-3 content of protozoa; the challenge is to increase protozoal flow to the small intestine, while maintaining sustainable rumen densities.

Once-daily budesonide inhalation suspension in infants and children < 4 and > or = 4 years of age with persistent asthma.

BACKGROUND: Budesonide inhalation suspension (Pulmicort Respules; AstraZeneca LP, Wilmington, DE), a nebulized corticosteroid, was developed for use in infants and young children with persistent asthma. OBJECTIVE: To compare the efficacy and safety of once-daily budesonide inhalation suspension in children < 4 years of age and in those > or = 4 years of age with persistent asthma. METHODS: A retrospective analysis stratified by age group was performed on data from two randomized, double-blind, placebo-controlled, parallel-group studies that evaluated the efficacy and safety of budesonide inhalation suspension 0.25 mg, 0.5 mg, or 1.0 mg once daily for 12 weeks in children 6 months to 8 years of age with persistent asthma. Clinical assessments included nighttime and daytime asthma symptoms, breakthrough medication use, adverse events, and hypothalamic-pituitary-adrenal-axis function. RESULTS: In both randomized studies, budesonide inhalation suspension demonstrated statistically significant improvement in nighttime and daytime asthma symptom scores compared with placebo. In the retrospective analysis of pooled data from these studies, the efficacy of budesonide was maintained when children were stratified by age group. Clinical improvements from baseline in nighttime and daytime asthma symptom scores were observed in both age groups at all budesonide inhalation suspension dose levels. No significant differences were observed between age groups in breakthrough medication use in any of the treatment groups. No differences were observed in the incidence of adverse events between the two age groups, and significant (P < 0.01) effect on hypothalamic-pituitary-adrenal-axis function was apparent only in children < 4 years of age at the 0.25-mg dose level. CONCLUSIONS: Once-daily budesonide inhalation suspension is effective in the treatment of persistent asthma in children aged < 4 and > or = 4 years of age.

Short-term and long-term safety of budesonide inhalation suspension in infants and young children with persistent asthma.

This article reviews the short-term and long-term safety profile of budesonide inhalation suspension (BIS) for nebulization in infants and young children with persistent asthma. Short-term safety (12 weeks) was assessed by pooling the results from the 3 randomized, double-blind, placebo-controlled, multicenter studies (studies A, B, and C) on the efficacy and safety of once- and twice-daily BIS. Long-term safety of BIS and conventional asthma therapy (CAT) was assessed in 52-week extension studies of the 12-week double-blind trials. CAT consisted of any available therapy for asthma; in 2 studies, CAT could have included treatment with inhaled glucocorticosteroids. Safety was assessed by monitoring adverse events (AEs), physical examinations, and basal and ACTH-stimulated plasma cortisol levels (in a subset of subjects). In the 52-week open-label extensions, the effects of BIS on growth velocity and skeletal age also were determined. In the 12-week studies, a total of 1017 subjects was evaluated for safety; totals of 231, 185, 229, 327, and 45 subjects were randomized to receive placebo or BIS at total daily doses of 0.25 mg, 0.5 mg, 1.0 mg, and 2.0 mg, respectively. Subject demographics and baseline asthma characteristics were similar across treatment groups, except that age, weight, height, and duration of asthma appeared higher in the 2. 0-mg daily dose group. For BIS groups, mean age was 58.9 months; mean weight was 20.3 kg; mean height was 108.9 cm, and mean duration of asthma was 3.2 years. There were no differences in the incidence, severity, or types of AEs reported among the BIS and placebo groups. There were no significant differences between placebo and BIS treatment groups in basal or ACTH-stimulated cortisol levels, physical examinations, clinical laboratory values, or fungal cultures. A total of 670 subjects completed the 52-week extension studies; 223 subjects received CAT and 447 received BIS. Median total daily doses of BIS ranged from 0.50 mg to 1.0 mg in the 3 studies, and the mean duration of treatment exposure was 304 +/- 119 days and 342 +/- 83 days in CAT and BIS groups, respectively. During the 52-week treatment period, the incidences of reported AEs were comparable between treatment groups and were mild-to-moderate in intensity; no new AEs occurred during the 52-week studies compared with 12-week studies. No significant differences were observed between BIS and CAT in basal or ACTH-stimulated cortisol levels, physical examinations, clinical laboratory values, or fungal cultures. There was a small but statistically significant reduction in growth velocity (a difference of 0.8 cm) in the BIS-treated group compared with the CAT group in study A. In studies B and C, growth velocity was not different between BIS and CAT groups. In pooled analyses, no statistically significant differences in growth velocity, standard median heights, or skeletal age were observed between BIS and CAT groups. Short-term and long-term treatment with BIS, over a wide range of doses, was well tolerated for the treatment of persistent asthma in infants and young children.

Caring for the orthopaedic patient receiving continuous ambulatory peritoneal dialysis.

Providing nursing care for patients with End stage renal disease (ESRD) receiving continuous ambulatory peritoneal dialysis (CAPD) provides a variety of challenges for the orthopaedic nurse. In ESRD the kidneys not only lose the ability to remove waste products and excess fluids, but also are unable to assist the body to use active vitamin D3 for calcium absorption. ESRD patients are at a high risk for developing fractures due to the kidneys' inability to excrete phosphate, resulting in elevated plasma phosphate and low plasma calcium levels resulting in osteodystrophy. Patients conduct peritoneal dialysis treatments independently after receiving an in-depth education program. It is important for the nurse to continue to foster patients' independence by encouraging self-administration of CAPD even during hospitalization. CAPD is carried out manually by instilling dialysis solution into the peritoneal cavity usually four times daily to remove excess fluids and metabolic waste products. Orthopaedic nurses face the challenge of not only caring for the patient's orthopaedic injury but also ensuring CAPD is implemented correctly. This article outlines common problems experienced by ESRD patients, principles of CAPD, and expected nursing care.

Exploration of factors that impact mode of death in the hemodialysis patient.

The purpose of this quantitative and explorative qualitative study was to examine the illness trajectory, social integration, role change, and social support that may have influenced hemodialysis patients' mode of death. A quantitative archival medical record review recorded patients' mode of death as listed on the End Stage Renal Disease (ESRD) Death Notification form. Exploratory interviews were conducted with the deceased hemodialysis patient's significant other to explore patient's illness trajectory, end-of-life experiences, social integration, role change, and social support. Seventeen patients experienced a sudden, unexpected, unintentioned death, and 15 patients experienced an intentioned death after withdrawal of hemodialysis. Qualitative indicators of illness trajectory indicated either a fairly slow downward course with a sudden unintentioned death or a rapid downward spiraling course resulting in intentioned death after withdrawal of hemodialysis. While it was unknown if significant others would report of individuals withdrawing from treatment who lacked social integration or social support, findings suggest that some individuals in this study withdrawing from hemodialysis exercised their rights to self-determination and right to refuse life-saving treatments. Although findings of this study are not generalizable, it may be advisable for nurses to engage patients and family members in discussions regarding advance directives, rights to refuse treatment, and withdrawal from hemodialysis prior to a change in the patient's illness trajectory.

A pharmacokinetic comparison of two oral liquid glucocorticoid formulations.

To compare pharmacokinetics of liquid prednisolone and prednisone solutions and to assess relative bioavailability, six healthy adult men were administered 15 mg of each formulation. Blood samples were obtained and assayed for plasma prednisolone concentrations by high-performance liquid chromatography. Peak concentration was significantly higher with liquid prednisolone (mean +/- SD 430.3 +/- 62.5 vs 333.0 +/- 27.8 ng/ml, p = 0.013), with similar times to peak concentration. Prednisolone liquid gave higher concentrations at every time point (statistically significant for all except 0.25 hrs after the dose), resulting in a significantly greater total area under the curve (2029.8 +/- 246.9 vs 1633.3 +/- 221.1 ng/ml.hour, respectively, p = 0.002). Clearance was slower for prednisolone (128.3 +/- 15.1 vs 149.1 +/- 17.6 ml/min/1.73 m2, p = 0.01), and the relative bioavailability of the prednisolone liquid using prednisone liquid as the reference standard was 116 +/- 14%. Thus, prednisolone liquid has similar pharmacokinetic characteristics as prednisone liquid, with improved bioavailability.

Summertime haze air pollution and children with asthma.

In order to investigate associations between summertime haze air pollution and asthma at an individual level, 52, 58, and 56 children (ages 7 to 13) attending a summer "asthma camp" were followed during the last week of June in 1991, 1992, and 1993, respectively. Most of the subjects had moderate to severe asthma. Daily records were kept of the environmental conditions, as well as of subject medication use, lung function, and medical symptoms. Air pollution was found to be significantly and consistently correlated with acute asthma exacerbations, chest symptoms, and lung function decrements. The pollutant most consistently associated with adverse health consequences was ozone (O3), although associations with sulfates and hydrogen ion suggest a possible role by fine particles as well. Effects were found to be roughly monotonic as a function of O3 concentration. Regression of morning (8:00 A.M.) to afternoon (5:00 P.M.) peak flow change on O3 indicated pulmonary function reductions similar to those previously reported for more active children without asthma. Moreover, analyses also indicated an increased risk of an asthma exacerbation and of experiencing chest symptoms of approximately 40% on the highest pollution day, relative to the mean. Based on these relative risk estimates, a rise in the 1-h daily maximal O3 from 84 ppb to 160 ppb was associated in this group with an increase from 20 to 28 (+/- 2) in the expected number of unscheduled medications administered/day, and from 29 to 41 (+/- 3) in the expected total number of chest symptoms/day. Thus, air pollution can be a major contributor to the respiratory problems experienced by children with asthma during the summer months.

Respiratory failure in children with acquired immunodeficiency syndrome and acquired immunodeficiency syndrome-related complex.

Acute respiratory failure has a high mortality in patients with acquired immunodeficiency syndrome (AIDS). This study was undertaken to determine the etiology of acute respiratory failure and the outcome of children with AIDS and AIDS-related complex. Records of 31 children with AIDS or AIDS-related complex admitted to the pediatric intensive care unit for acute respiratory failure throughout a 46-month period were reviewed. Acute respiratory failure was due to Pneumocystis carinii pneumonia in 13, cytomegalovirus pneumonia in six, bacterial pneumonia in five, severe bacterial sepsis in four, Candida pneumonia in two, and a giant cell pneumonia in one patient. In addition, 11/19 patients with acute respiratory failure due to P carinii pneumonia or cytomegalovirus had superinfections with bacteria or Candida. Of the total of 19 primary and secondary bacterial infections, Pseudomonas aeruginosa was responsible in ten and Klebsiella pneumoniae in three children. Five children (16%) survived until pediatric intensive care unit discharge; three died within 6 months. The causes of acute respiratory failure were not significantly different in survivor and nonsurvivor groups. It is concluded that, in addition to P carinii pneumonia and cytomegalovirus pneumonia, bacterial infections (especially due to Pseudomonas and other Gram-negative organisms) are important causes of respiratory failure. The high mortality and grim ultimate prognosis seen may have implications for pediatricians attempting to identify the proper limits of medical intervention for this group of patients.

Use of the iced cystogram to differentiate bladder neck and external sphincter obstruction.

An iced cystogram was done on 31 patients with neurogenic bladder and voiding dysfunction. We observed 5 distinguishable patterns upon which therapeutic measures to improve balance could be based. We found the iced cystogram to be a simple, inexpensive yet reliable technique to assess detrusor sphincter imbalance. With the information obtained from this study the therapeutic options were delineated more clearly and the results of the treatment were made more predictable.

Phenoxybenzamine in neurogenic bladder dysfunction after spinal cord injury. I. Voiding dysfunction.

Phenoxybenzamine is a welcomed adjunct in the pharmacologic management of patients with neurogenic bladder dysfunction resulting from spinal cord trauma. Side effects are infrequent. Bladder balance was predictably and effectively achieved and maintained in patients with 1) lower motor neuron lesions, 2) upper motor neuron lesions and coexisting autonomic dysreflexia and 3) intact sympathetic innervation and upper motor neuron bladders. The response was unpredictable in patients with upper motor neuron lesions without coexisting dysreflexia.

Phenoxybenzamine in neurogenic bladder dysfunction after spinal cord injury. II. Autonomic dysreflexia.

Phenoxybenzamine blockade of the alpha receptor site can abolish the vascular and internal sphincter responses in patients with chronic recurrent autonomic dysreflexia associated with bladder filling or contraction. The life-threatening hypertensive response is suppressed by this medication. Therefore, the drug is a beneficial adjunct in the pharmacologic management of autonomic dysreflexia. When the drug is used patients can be maintained free of a catheter. The drug had no serious side effects at the dose regimen used. One particularly significant advantage is its long duration of action--patients occasionally can skip doses of medication and not suffer acute symptoms.

Erections and sexual function in post-sphincterotomy bladder neck patients.

A study of 131 patients who underwent sphincterotomy and bladder neck incision was done to determine changes in postoperative erectile and sexual function. A complete, permanent loss of erectile function was noted in 8.2 per cent of the patients and diminished erectile function was noted in 16.8 per cent. Unchanged or improved erections were noted in 74.8 per cent of the patients, while a complete loss of ability to engage in vaginal sexual intercourse, which had been present preoperatively, was sustained by 3.9 per cent of patients with diminished erections suffered no impairment of their preoperative sexual ability. Unaltered, improved or induced sexual function was present in 96.1 per cent of the patients postoperatively.

Salmonella infection and the genitourinary system.

Six cases of severe salmonella genitourinary infection and a case of salmonella septicemia after prostatectomy are reported. The mechanism whereby the urinary tract is involved in salmonellosis is described, as are the different manifestations of genitourinary salmonellosis. Host factors predisposing to the development of genitourinary salmonella infection include other urologic pathology, malignant neoplasms and states of depressed immunity. Recommendations are made with regard to the diagnosis and management of this sometimes lethal condition.

Papillary adenocarcinoma of prostate.

Papillary adenocarcinomas of the prostate are rare tumors which may arise from the prostatic ducts and the utricle; 2 cases are described. The diagnosis of these tumors is best established by cystourethroscopy and transurethral resection. The more common prostatic acinar adenocarcinoma is frequently associated with these tumors. The histopathologic recognition of papillary adenocarcinoma of the prostate and its differentiation from acinar adenocarcinoma is important since the natural history and response to treatment may be different.

Renal angiomyolipoma: two varieties.

Two cases of symptomatic renal angiomyolipoma are presented, and their distinctive clinical, radiologic, and histologic features are discussed. In the first case the scout film demonstrated radiolucency of the tumor which helped to distinguish it from carcinoma. In the second case, which was associated with tuberous sclerosis, the renal lesion was large and unifocal, and the local lymph nodal involvement with tumor raised the possibility of malignant transformation.