Salvage of blood urea nitrogen in sheep is highly dependent on plasma urea concentration and the efficiency of capture within the digestive tract.

The aims of this study were 1) to determine whether transfer of blood urea to the gastrointestinal tract (GIT) or the efficiency of capture of urea N within the GIT is more limiting for urea N salvage, and 2) to establish the relationship between plasma urea concentration and recycling of urea N to the GIT. We used an i.v. urea infusion model in sheep to elevate the urea entry rate and plasma concentrations, thus avoiding direct manipulation of the rumen environment that otherwise occurs when feeding additional N. Four growing sheep (28.1 +/- 0.6 kg of BW) were fed a low-protein (6.8% CP, DM basis) diet and assigned to 4 rates of i.v. urea infusion (0, 3.8, 7.5, or 11.3 g of urea N/d; 10-d periods) in a balanced 4 x 4 Latin square design. Nitrogen retention (d 6 to 9), urea kinetics([(15)N2]urea infusion over 80 h), and plasma AA were determined. Urea infusion increased apparent total tract digestibility of N (29.9 to 41.3%) and DM (47.5 to 58.9%), and N retention (1.45 to 5.46 g/d). The plasma urea N entry rate increased (5.1 to 21.8 g/d) with urea infusion, as did the amount of urea N entering the GIT (4.1 to 13.2 g/d). Urea N transfer to the GIT increased with plasma urea concentration, but the increases were smaller at greater concentrations of plasma urea. Anabolic use of urea N within the GIT also increased with urea infusion (1.43 to 2.98 g/d; P = 0.003), but anabolic use as a proportion of GIT entry was low and decreased (35 to 22%; P = 0.003) with urea infusions. Consequently, much (44 to 67%) of the urea N transferred to the GIT returned to the liver for resynthesis of urea (1.8 to 9.2 g/d; P < 0.05). The present results suggest that transfer of blood urea to the GIT is 1) highly related to blood urea concentration, and 2) less limiting for N retention than is the efficiency of capture of recycled urea N by microbes within the GIT.

Application of stable isotopes and mass isotopomer distribution analysis to the study of intermediary metabolism of nutrients.

Genomic investigations in animals have begun to reveal the metabolic and physiological functions of genes and protein products. However, a thorough understanding of the genomic roadmaps will require investigative approaches that yield qualitative and quantitative information on the activities, fluxes, and connectivity of pathways involved in nutrient use in farm animals; that is, the metabolic phenotype. Recently, the commercial availability of stable isotope (13C, 15N, 2H)-labeled compounds and highly accurate mass spectrometers has made it possible to probe the details of metabolic pathways involved in macronutrient use. For years, the biological sciences have exploited uniformly 13C-labeled substrates (e.g., glucose, amino acids, nucleic acids) and 13C-mass isotopomer distribution (MID) in their metabolic investigations, whereas their use in the animal sciences is very limited. When [U-13C] substrates are fed, infused, or added to cell incubations, the 13C-skeletons distribute throughout metabolic networks. 13C-Mass isotopomer distribution in intermediates and end products of the pathways provides a signature of the fluxes and activities of pathway enzymes traveled by the precursor molecule. This paper highlights aspects of animal nutrition and metabolism in which [U-13C] substrates and MID can be applied to investigations of amino acid, carbohydrate, and fat metabolism. We will focus on [U-13C] glucose as a tracer in chickens, fish, sheep, and cell cultures to investigate the interconnectivity of the pathways of macronutrient and nucleic acid metabolism, and provide demonstration of the central position of the Krebs cycle in preserving metabolic flexibility via anaplerotic and cataplerotic sequences. Exploitation of this approach in animal sciences offers endless opportunities to provide missing details of the biochemical networks of nutrient use that may prove to be strictly under genomic control.

Metabolic fates of ammonia-N in ruminal epithelial and duodenal mucosal cells isolated from growing sheep.

The objective of this experiment was to determine the capability of ruminant gut tissues to detoxify ammonia-N using short-term incubations of isolated cells in vitro. Ruminal epithelial cells (REC) and duodenal mucosal cells (DMC) were isolated from growing Texel-Polypay ram lambs (n = 4) fed a pelleted forage:concentrate-based diet. Immediately after isolation, primary cells were incubated for 60 min with glucose (1mM), glutamate (1mM), [15N]ammonium chloride (5, 10, 20, or 40 mM), and 1 of 4 combinations of substrates (1 mM each) that could support urea synthesis [control, N-carbamoylglutamate (NCG); NCG + ornithine (ONCG); and ONCG + aspartate (AONCG)]. Treatments were arranged in a 4 x 4 factorial design. Incorporation of ammonia-15N into alanine, citrulline, arginine, and urea was determined by gas chromatography-mass spectrometry. For both cell types, ammonia-N transfer to alanine was lower when incubation medium contained NCG compared with control, whereas use of ammonia-N for net alanine synthesis increased quadratically with ammonia concentration regardless of substrate treatment. For REC, ammonia-N was not incorporated into citrulline, arginine, or urea, nor into arginine or urea by DMC. Ammonia-N use for net citrulline synthesis exhibited an inverse relationship with ammonia concentration, decreasing linearly as media ammonia concentration increased. Thus, ala-nine synthesis may be a significant metabolic pathway for ruminant gut tissues to detoxify ammonia-N when it is presented luminally at high concentrations as compared with detoxification by the ornithine-urea cycle. Furthermore, DMC do exhibit a metabolic capability to incorporate ammonia-N into citrulline, but low or absent activity of downstream enzymes of the ornithine-urea cycle appears to limit ammonia-N transfers to urea.

Visual functioning and quality of life in the SubFoveal Radiotherapy Study (SFRADS): SFRADS report 2.

AIMS: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. METHODS: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6 x 2 Gy fractions to the macula of an affected eye versus observation. Patients with AMD, aged 60 years or over, in three UK hospital units, who had subfoveal CNV and a visual acuity equal to or better than 6/60 (logMAR 1.0). METHODS: Data from 199 eligible participants who were randomly assigned to 12 Gy teletherapy or observation were available for analysis. Visual function assessment, ophthalmic examination, and fundus fluorescein angiography were undertaken at baseline and at 3, 6, 12, and 24 months after study entry. To assess patient centred outcomes, subjects were asked to complete the Daily Living Tasks Dependent on Vision (DLTV) and the SF-36 questionnaires at baseline, 6, 12, and 24 months after enrolment to the study. Cross sectional and longitudinal analyses were conducted using arm of study as grouping variable. Regression analysis was employed to adjust for the effect of baseline co-variates on outcome at 12 months and 24 months. RESULTS: Both control and treated subjects had significant losses in visual functioning as seen by a progressive decline in mean scores in the four dimensions of the DLTV. There were no statistically significant differences between treatment and control subjects in any of dimensions of the DLTV at 12 months or 24 months after study entry. Regression analysis confirmed that treatment status had no effect on the change in DLTV dimensional scores. CONCLUSIONS: The small benefits noted in clinical measures of vision in treated eyes did not translate into better self reported visual functioning in patients who received treatment when compared with the control arm. These findings have implications for the design of future clinical trials and studies.

Urea synthesis by ruminal epithelial and duodenal mucosal cells from growing sheep.

The objective was to determine whether ruminant gut tissues have the capability to synthesize urea in a short-term incubation. Mixed primary cell cultures containing ruminal epithelial (REC) or duodenal mucosal cells (DMC) were isolated from growing sheep (n = 4) fed a mixed forage-concentrate diet. Cells were incubated (90 min) in a Krebs salts-based buffer with either acetate (5 mM) or propionate (5 mM) plus a combination of substrate intermediates (5 mM) for urea synthesis: arginine, aspartate + citrulline (AspC), aspartate + ornithine + ammonia (AspON), or AspON + N-carbamoylglutamate (AspONG) in a 2 x 4 factorial arrangement of treatments. Volatile fatty acid, propionate vs. acetate, did not influence net urea synthesis. For REC, net urea synthesis (nmoles x (10(6) cells)(-1) x 90 min(-1)) was greatest with Arg (54.5 +/- 6.3) followed by AspC (4.6 +/- 1.1) and AspONG (3.6 +/- 1.4). For DMC, net urea synthesis for Arg (2.1 +/- 0.7) and AspONG (1.9 +/- 0.7) treatments was greater than for AspC (0.3 +/- 0.7) and AspON (-0.6 +/- 0.7) treatments. Thus, for both REC and DMC, arginase activity appeared to be sufficient for catabolism of arginine to urea. Furthermore, greater urea synthesis from ammonia, ornithine and aspartate in the presence of the N-acetylglutamate analogue suggests that carbamoyl phosphate synthetase is probably rate-limiting for urea synthesis and ammonia detoxification by ruminant gut tissues.

Prophylactic laser treatment appears to promote choroidal neovascularisation in high-risk ARM: results of an interim analysis.

PURPOSE: The Drusen Laser Study (DLS) of high-risk age-related maculopathy (ARM) is a randomised, controlled clinical trial designed to answer two questions: (1). Do drusen resolve after macular laser photocoagulation (2). Does macular laser photocoagulation prevent choroidal neovascularisation (CNV) in high-risk eyes? In this report, we present the results of the interim, pooled analysis of CNV prophylaxis for patients in the Unilateral Group of the DLS. METHODS: The DLS is a randomised controlled clinical trial of prophylactic macular photocoagulation for high-risk ARM. Patients in the Unilateral Group had a neovascular complication in the first eye; their fellow eye (Study Eye) had visual acuity of 6/12 or better and drusen. Following informed consent, patients were randomised to the Treatment Group or the No Treatment Group. Patients randomised to treatment received 12 light spots of argon laser photocoagulation to their Study Eye: four burns were placed 750 microm from the centre of the fovea at 12, 3, 6, and 9 o'clock, and the eight remaining burns were placed 1500 microm from the centre of the fovea at 12, 1:30, 3, 4:30, 6, 7:30, 9, and 10:30 o'clock. Drusen were treated directly only if they were present at the protocol treatment locations. All patients were followed in an identical fashion at regular intervals. Best-corrected visual acuity was measured and recorded by a masked observer. Fluorescein angiography was performed at baseline and yearly review, as well as nonprotocol visits if symptoms suggested CNV. Five clinical centres utilised and conformed to a common DLS protocol. Patient care and data collection methodologies were deemed sufficiently similar to permit a pooled data analysis. RESULTS: There were 156 patients included in the interim analysis, and timed information was available on 153. CNV occurred in 21 of 81 (26%) patients in the Treatment Group and in 13 of 75 (17%) patients in the No Treatment Group (P=0.19). Kaplan-Meier survival analysis showed earlier onset of CNV in the Treatment Group compared to patients in the No Treatment Group (statistical significance not calculated). Visual acuity loss at 2 years occurred in nine of 54 (17%) patients in the Treatment Group compared to the two of 48 (4%) patients in the No Treatment Group (P=0.056). CONCLUSIONS: We are only the second group to identify possible laser-induced CNV despite other similar studies in progress. Equipoise of the DLS investigators was lost, and recruitment was halted. We feel ethically bound to notify the ophthalmic community of this finding.

Visual outcomes in the subfoveal radiotherapy study: a randomized controlled trial of teletherapy for age-related macular degeneration.

OBJECTIVE: To determine whether teletherapy with 6-mV photons can reduce visual loss in patients with subfoveal choroidal neovascularization in age-related macular degeneration. DESIGN: A multicenter, single-masked, randomized controlled trial of 12 Gy of external beam radiation therapy delivered to the macula of an affected eye vs observation only. SETTING: Three United Kingdom-based hospital units. PARTICIPANTS: Patients with age-related macular degeneration, aged 60 years and older, who had subfoveal choroidal neovascularization and a visual acuity of 20/200 (logMAR 1.0) or better. METHODS: Two hundred three patients were randomly assigned to radiotherapy or observation. Treatment was undertaken at designated radiotherapy centers, and patients assigned to the treatment group received a total dosage of 12 Gy of 6-mV photons in 6 fractions. Follow-up was scheduled at 3, 6, 12, and 24 months. After excluding protocol violators, the data from 199 patients were analyzed. MAIN OUTCOME MEASURES: The primary outcome measure was mean loss of distance visual acuity in the study eye at 12 and 24 months. Other outcome variables analyzed were near visual acuity and contrast sensitivity. The proportions of patients losing 3 or more or 6 or more lines of distance and near acuity and 0.3 or more or 0.6 or more log units of contrast sensitivity at each follow-up were also analyzed. RESULTS: At all time points, mean distance visual acuity was better in the radiotherapy-treated group than in the control group, but the differences did not reach statistical significance. At 24 months, analysis of the proportions of patients with loss of 3 or more (moderate) (P =.08) or 6 or more (severe) (P =.29) lines of distance vision showed that fewer treated patients had severe losses, but there was no statistically significant difference between groups. For near visual acuity, although there was no evidence of treatment benefit at 12 and 24 months, a significant difference in favor of treatment was present at 6 months (P =.048). When analyzed by the proportions of patients losing 3 lines of contrast sensitivity, there was a significant difference in favor of treatment at 24 months (P =.02). No adverse retinal effects were observed during the study, but transient disturbance of the precorneal tear film was noted in treated patients. CONCLUSION: The results of the present trial do not support the routine clinical use of external beam radiation therapy in subjects with subfoveal choroidal neovascularization in age-related macular degeneration.

Modified atmosphere packaged cheddar cheese shreds: influence of fluorescent light exposure and gas type on color and production of volatile compounds.

The influences of fluorescent light exposure and packaging atmosphere on the headspace volatiles and color of Cheddar cheese shreds were evaluated using gas chromatography-mass spectrometry and spectrocolorimetry, respectively. Cheddar cheeses were packaged under atmospheres of 100% carbon dioxide or 100% nitrogen and stored at 4 degrees C under fluorescent light for 6 weeks. Cheeses stored under carbon dioxide contained higher concentrations of aldehydes and fatty acids and lower concentrations of alcohols and esters than cheeses stored under nitrogen. Carbon dioxide atmospheres potentiated light-induced oxidation in shredded Cheddar cheeses, as evidenced by aldehyde and fatty acid headspace volatiles measured following storage. Color bleaching occurred only in cheeses packaged under carbon dioxide and exposed to light. The shift in color is proposed to be due to an interaction between carbon dioxide and high-intensity light, leading to the oxidation of the pigment molecule, bixin. The results have significant implications for procedures used to handle and store pigmented cheeses to ensure desirable flavor and consumer acceptability.

Long-term drusen study.

PURPOSE: To determine the yearly incidence of visual loss in the fellow eyes of patients with unilateral neovascular age-related macular degeneration (ARMD) and to assess the drusen characteristics portending the greatest risk for this outcome. METHODS: A total of 101 patients with unilateral exudative ARMD and drusen only in the fellow eye were entered into the study and prospectively followed up to 9 years. Visual acuity, color fundus photography, fluorescein angiography, and grading of drusen characteristics were obtained for each patient on entry into the study. Patients were followed at annual intervals with color fundus photography. The study endpoint was the development of choroidal neovascularization (CNV) or geographic atrophy (GA) in the fellow eye. RESULTS: Yearly incidence rates for the development of an endpoint lesion were between 5 and 14%. The risk of CNV peaked at 4 years and dissipated thereafter. Longer follow-up was associated with a slightly increased incidence of GA. Greater drusen number was most highly associated with the development of an endpoint lesion. Drusen size and confluence were also significant. CONCLUSIONS: The risk of CNV in patients with ARMD is heralded by an increase in the number, size, and confluence of drusen. This risk eventually declines and is followed by later increased risk of GA.

Fluorescein angiographic abnormalities after prophylactic macular photocoagulation for high-risk age-related maculopathy.

PURPOSE: Initial studies suggest that drusen associated with age-related maculopathy resolve in response to laser photocoagulation; there are conflicting reports regarding whether this treatment might prevent neovascular complications and blindness. The goal of the Drusen Laser Study is to maintain good visual acuity in eyes at the highest risk for neovascular complications of age-related maculopathy. In this report, we alert the ophthalmic community to possible laser-induced complications in patients treated within the context of this clinical trial. METHODS: A double-masked, randomized, controlled clinical trial of prophylactic macular photocoagulation for high-risk age-related maculopathy is in progress. Patients randomly assigned to treatment received a ring-type distribution of 12 light spots of argon laser photocoagulation. Drusen were treated directly only if they were present at the protocol treatment locations. Fluorescein angiography was performed in all patients at yearly review, and at nonprotocol visits if symptoms or clinical examination were suggestive of choroidal neovascularization. RESULTS: Fluorescein angiographic abnormalities suggestive of choroidal neovascularization have been seen in treated eyes only: one patient in the pilot study and six patients in the Drusen Laser Study. No fluorescein angiographic abnormalities were seen in eyes of control subjects. CONCLUSIONS: Laser photocoagulation in high-risk age-related maculopathy may induce choroidal neovascularization and, therefore, is not recommended outside the context of a randomized, controlled clinical trial.

The use of corticosteroids for choroidal neovascularisation in young patients.

PURPOSE: To investigate the role of systemic corticosteroids in the treatment of sight-threatening choroidal neovascularisation (CNV) in patients with punctate inner choroidopathy (PIC) and multifocal inner choroiditis (MIC). METHODS: Twelve eyes of 10 patients with evidence of PIC or MIC with recent visual symptoms were identified. All eyes had CNV within the foveal avascular zone on fundus fluorescein angiography (FFA). Systemic oral prednisolone at an initial dose of 1 mg/kg (60-80 mg) was given for 3-5 days and the dose was subsequently tapered. Changes in best corrected visual acuity and leakage on FFA were recorded during follow-up. Systemic side-effects of the corticosteroids were monitored. RESULTS: In 10 of 12 eyes vision improved or stabilised. Leakage on FFA resolved in 9 eyes and was reduced in 3. Four patients required more than one course of oral corticosteroids. One patient was maintained on low-dose oral corticosteroids for recurrent CNV activity. No systemic complications from the treatment were observed. CONCLUSION: A course of oral corticosteroids in healthy young patients with subfoveal CNV in PIC or MIC may reduce subretinal vascular leakage and stabilise vision when no other proven treatment option is available.

Prophylactic laser treatment to fellow eyes of unilateral retinal pigment epithelial tears.

PURPOSE: To evaluate prophylactic laser treatment of the macula in reducing the risk of visual loss in the fellow eye of patients with a retinal pigment epithelial tear caused by age-related macular degeneration in the first eye. METHODS: In a prospective study, 12 patients with a retinal pigment epithelial tear in one eye caused by age-related macular degeneration and drusen in the fellow eye received prophylactic laser treatment of the retina in their fellow eyes and were followed up for 2 years or more after prophylactic treatment. RESULTS: In 12 fellow eyes that received prophylactic laser treatment, a reduction in best-corrected visual acuity to 20/80 or worse occurred in one (8%) of 12 eyes in the first year and two (18%) of the remaining 11 eyes in the second year after treatment. The cumulative risk of visual loss in the treated fellow eye was 25% in 2 years. CONCLUSIONS: In historical control subjects in a natural history study of patients with retinal pigment epithelial tear in one eye, central visual loss occurred in 16 (37%) of 43 eyes in the first year and in seven (30%) of 23 eyes in the second year for a cumulative loss of 59% in the first 2 years. Compared with these historical control subjects, our findings suggest that visual loss in the fellow eyes of patients with a retinal pigment epithelial tear in the first eye is reduced by prophylactic low intensity laser photocoagulation of the macula.

Elevated plasma corticosterone concentrations influence the onset of rigor mortis and meat color in broilers.

This experiment was conducted to determine the effect of elevated plasma corticosterone (CORT) levels on meat quality characteristics. Male broilers (Arbor Acres) were either 1) fed a diet containing corticosterone (CORT) prior to processing, 2) transported by truck for 3 h before processing, or 3) processed without either of the above treatments. Six crates of birds (10 birds per crate; two crates per treatment) were stunned or killed using CO2 gas. Six birds per crate were processed and blood samples were collected during exsanguination for plasma CORT analysis. Meat samples were collected from carcasses either at 20 min or at 4 h post-mortem. At each sampling time (ST), Pectoralis superficialis samples were collected and either individually quick frozen (IQF) in liquid nitrogen or aged on ice (AOI) for 24 h prior to pH, ratio of inosine to adenosine nucleotides (R-value), cooking loss, shear value, and color analyses. The IQF Biceps femoris samples were used for pH, R-value, color, and heme pigment analysis. Mean (+/- SEM) CORT concentrations were 12.9+/-2.57, 11.7+/-1.38 and 7.9+/-0.79 ng/mL, respectively, in the CORT, transported, and control groups. There were significant treatment by ST (P < 0.05) and ST (P < 0.001) effects on the R-value of IQF P. superficialis samples. The CORT group had the highest L* value (P < 0.01) and the lowest a* value (P < 0.06). There was also a significant main effect of ST on shear values (P < 0.05) of AOI P. superficialis samples, with the means higher at 4 h than at 20 min post-mortem. The R-value of IQF B. femoris samples was markedly influenced by treatment (P < 0.001) and ST (P < 0.001). The results indicate that artificially elevating circulating CORT concentrations results in lighter meat color in broilers.

Laser treatment in subjects with high-risk clinical features of age-related macular degeneration. Posterior pole appearance and retinal function.

OBJECTIVES: To verify that a few laser lesions in the posterior pole can cause drusen to resolve in patients with age-related macular degeneration, and to document central retinal sensitivity as drusen resolve. DESIGN: In a pilot study, 12 patients considered to be at high risk for sight-threatening complications from age-related macular degeneration were treated with 12 argon laser lesions in the posterior pole, with review for 12 to 24 months. RESULTS: Choroidal neovascularization developed in 1 patient 8 months after treatment, with consequent loss of central vision. In 9 of the remaining 11 patients, high-risk characteristics of drusen were reduced. Four patients had retinal pigment epithelial depigmentation, and all maintained 20/40 visual acuity at 12 months. One patient lost 3 lines of vision due to geographic atrophy after 12 months. Scotopic retinal threshold was elevated before treatment in 8 patients, compared with an age-matched comparison group. Of these, 4 patients underwent retesting 3 to 6 months after treatment, and all had improved thresholds, but only 1 patient sustained the improvement at 12 months. At 12 months, 3 of the 8 patients showed an improvement in their mean retinal threshold. Of those in whom the mean retinal threshold worsened, the mean elevation in threshold was not more than 0.6 log units. CONCLUSIONS: A few laser lesions in the posterior pole leads to resolution of drusen. There does not appear to be an increased risk for choroidal neovascularization. Retinal threshold measurements show no indication of geographic atrophy at 1 year, but cannot be excluded as a late outcome. Laser treatment may reduce the risk for profound sight-threatening lesions in age-related macular degeneration.

Ocular manifestations in autosomal dominant retinitis pigmentosa with a Lys-296-Glu rhodopsin mutation at the retinal binding site.

A lysine to glutamic acid substitution at codon 296 in the rhodopsin gene has been reported in a family with autosomal dominant retinitis pigmentosa. This mutation is of particular functional interest as this lysine molecule is the binding site of 11-cis-retinal. The clinical features of a family with this mutation have not been reported previously. We examined 14 patients with autosomal dominant retinitis pigmentosa and a lysine-296-glutamic acid rhodopsin mutation. Four had detailed psychophysical and electrophysiological testing. Most affected subjects had severe disease with poor night vision from early life, and marked reduction of visual acuity and visual field by their early forties. Psychophysical testing showed no demonstrable rod function and severely reduced cone function in all patients tested.

Allopurinol inhibition of neutrophilic alveolar response during hyperoxia.

Allopurinol is a potent xanthine oxidase inhibitor that has been administered to animals to protect tissues from oxidant injury. We hypothesized that allopurinol may protect against oxidant injury by inhibiting the inflammatory response. Male Sprague-Dawley rats were injected daily with vehicle or allopurinol and compared with noninjected controls. Animals were exposed to room air or 90% oxygen for 14 days. At the end of the exposure period, all animals were lavaged and bronchoalveolar lavage fluid (BALF) was examined for cell counts, lactate dehydrogenase (LDH), and protein. BALF neutrophils were significantly increased in oxygen-exposed noninjected controls (33 +/- 7 x 10(3)/mm3) and also in the vehicle-inoculated oxygen-exposed animals (43 +/- 6 x 10(3)/mm3). Allopurinol treatment resulted in a decrease in the neutrophilic alveolar response in oxygen-exposed animals (5.3 +/- 4 x 10(3)/mm3, P < 0.001). These data reveal that oxygen exposure produces a neutrophilic alveolar response that is attenuated by allopurinol treatment. BALF protein and LDH were significantly increased in all inoculated and noninoculated oxygen-exposed animals compared with air-exposed animals. Therefore, allopurinol decreases the neutrophilic alveolar response produced by a hyperoxic exposure in the rat but does not decrease lung injury as assessed by alveolar LDH and protein release.

Preliminary study of a new intraocular method in the diagnosis and treatment of Propionibacterium acnes endophthalmitis following cataract extraction.

Late endophthalmitis, due to Propionibacterium acnes, developed in three patients following uncomplicated extracapsular cataract extraction and posterior chamber intraocular lens (PC-IOL) insertion. Cultures from the capsular bag yielded P. acnes in all three. With topical anesthesia and through an anterior chamber paracentesis, culture specimens were taken from and clindamycin irrigated into the capsular bag. Filtered 100% oxygen was introduced into the anterior chamber in two; the third also received an injection of gentamicin and dexamethasone into the capsular bag. After treatment, two patients received oral antibiotics; one received hyperbaric oxygen therapy. Visual acuity was improved and inflammation reduced in all three. However, after treatment, ocular toxic effects due to clindamycin were suspected in one. This approach offers several clear advantages, including topical anesthesia, outpatient management, elimination of the need for vitrectomy, and retention of the intraocular lens (IOL).