Use of radio-frequency identification technology to assess the frequency of cattle visits to mineral feeders.

Three experiments were conducted to evaluate the frequency of visits to a mineral feeder equipped with radio-frequency identification (RFID). In Exp. 1, twelve heifers (Braford, Brahman, and White Angus; n = 4/breed) were fitted with RFID ear tags and placed into a pasture with access to a RFID-equipped mineral feeder. Number of visits were greater (P ≤ 0.05) during daytime than the night period. Brahman and Braford heifers favored (P ≤ 0.05) daytime than night period. White Angus heifers did not display a specific period preference (P = 0.32). In Exp. 2, Black Angus and Brahman cows (n = 15 and 19, respectively) were placed into a pasture with access to a RFID-equipped mineral feeder. Brahman cows made more (P < 0.01) visits to the mineral feeder than Black Angus cows. There were no breed differences on the number of visits during the morning (P = 0.25) and night (P ≤ 0.25) periods, but Brahman cows made more (P ≤ 0.05) visits to the mineral feeder in the afternoon period than Black Angus cows. In Exp. 3, the location of the mineral feeder was tested using 3 groups of Bos indicus-influenced heifers (n = 12/group). The mineral feeder was moved weekly within pasture. The number of visits to the mineral feeder differed for each location (P < 0.001) with visits being greatest when mineral feeder was placed near supplement and water, followed by center of the pasture, and lastly in the shade.

Maternal prepartum supplementation of protein and energy and body condition score modulated the performance of Bos indicus-influenced cow-calf pairs.

Retrospective analyses were performed on a dataset of 1188 fall-calving, Brangus cow-calf pairs. Analyses 1 sorted cows according to their initial body condition score (BCS < 5 vs. ≥ 5) and whether they received (SUP) or not (NOSUP) prepartum supplementation of protein and energy. Analyses 2 sorted cows according to their calving BCS (BCS < 5 or ≥ 5) and BCS change from calving until the start of the breeding season (lost, maintained, or gained). Cows were not estrus synchronized and were assigned to natural breeding for 90 days. Prepartum supplementation increased (P = 0.04) pregnancy percentage in cows with initial BCS < 5 but not (P = 0.20) with initial BCS ≥ 5. Calf weaning weight was greatest (P ≤ 0.04) for calves born from SUP cows with an initial BCS ≥ 5 and did not differ (P ≥ 0.56) among all remaining groups. Among cows with calving BCS < 5, pregnancy percentage were less (P = 0.05) for cows that lost vs. maintained/gained BCS. Postpartum BCS change did not (P ≥ 0.16) impact pregnancy percentage of cows calving at BCS ≥ 5. Calf weaning weight increased (P < 0.01) for cows calving with BCS ≥ 5 vs. < 5 and was not impacted (P = 0.47) by postpartum BCS change. Therefore, precalving supplementation improved reproduction of cows with BCS below optimal and weaning weight of calves born from cows with BCS above optimal, whereas calving BCS was the major factor affecting postpartum BCS change and cow reproductive performance.

Fibroblast growth factor-2 induced chondrocyte cluster formation in experimentally wounded articular cartilage is blocked by soluble Jagged-1.

INTRODUCTION: Basic fibroblast growth factor (FGF2) is a mitogen for articular chondrocytes. Cell death frequently occurs upon cartilage wounding and is evident during the progression of osteoarthritis. We hypothesised that incubation of wounded articular cartilage with exogenously added FGF2 would enhance cartilage repair, replacing dead cells through increased cell proliferation. METHODS: Articular cartilage from the metacarapalphalangeal joint of immature bovine steers was wounded in situ, then incubated in vitro in the continual presence or absence of FGF2. Cellular proliferation was expressed as a ratio of cell density of a fixed area between wounded and adjacent cartilage. Immunolabelling revealed the incorporation of bromodeoxyuridine and localisation of collagen type VI and Notch1 epitopes. gamma-secretase inhibitor N-[N-(3,5-Difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester and soluble Jagged1 ligand (sJ1) were used to analyse the function of Notch signalling in this wound model. RESULTS: FGF2 induced cellular proliferation at the margins of wounded articular cartilage, where proliferative chondrocytes adopted a cluster configuration. Collagen type VI protein was expressed by chondrocytes in clusters, as was Notch1. Cellular proliferation was not affected by inhibition of gamma-secretase dependent Notch1 signalling. Binding of sJ1 to Notch1 receptors in FGF2 treated cartilage inhibited proliferation. CONCLUSION: Addition of FGF2 induces rapid chondrocyte proliferation in wounded cartilage, chondrocytes adopt a cluster morphology and also express Notch1. Binding of sJ1 to Notch1 causes apoptosis overriding a proliferative response. This study may shed some light on the significance of increased Notch1 expression and its localisation in chondrocyte clusters in osteoarthritic cartilage.

28-day survival rates of 6676 neonates with birth weights of 1250 grams or less.

Survival rates specific for birth weight, gestational age, sex, and race are described for 6676 inborn neonates who weighed less than 1251 g at birth and were born during 1986 through 1987. Overall 28-day survival increased with gestational age and birth weight, from 36.5% at 24 weeks' gestation to 89.9% at 29 weeks' gestation, or from 30.0% for neonates of 500 through 599 g birth weight to 91.3% for neonates of 1200 through 1250 g. The expected birth weight-specific survival advantage for female neonates and black neonates diminished when the data were controlled for gestational age, showing that certain previously reported survival advantages are based on lower birth weight for a given gestational age. Multivariate analysis showed that all tested variables were significant predictors for survival, in order of descending significance: gestational age and birth weight, sex, race, single birth, and small-for-gestational-age status. The powerful effect of gestational age on survival highlights the need for an accurate neonatal tool to assess the gestational age of very low birth weight neonates after birth.

Acuity card assessment of visual function in the cryotherapy for retinopathy of prematurity trial.

The primary outcome measure of the effectiveness of cryotherapy in the original design of the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) was the anatomic status of the retina, as documented by fundus photography 3 months and 12 months after infants had received treatment. The authors describe the addition of a measurement of visual function, the Acuity Card procedure, to the CRYO-ROP study. After training, four visual-acuity testers attempted to measure monocular grating acuity in all randomized infants and approximately one fourth of the natural-history infants in the study, tested at 1 year postcryotherapy or 1 year postterm. In 95% of infants on whom testing was attempted, monocular acuity values from each eye were obtained. Interobserver test-retest results on 25 eyes of 13 randomized infants agreed to within one octave or better in all but one of the eyes. The high testability rate and good interobserver agreement suggest that the Acuity Card procedure has been a successful method of assessing visual function in the CRYO-ROP study.

Comparison of recognition and grating acuities in very-low-birth-weight children with and without retinal residua of retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

PURPOSE: To compare recognition (letter) and resolution (grating) acuity in eyes with and without retinopathy of prematurity (ROP) residua. METHOD: Letter acuity measured with the crowded HOTV chart or pocket cards (Good-Lite), and grating acuity measured with the Teller Acuity Card (TAC) procedure, were compared at the 3 1/2- and 4 1/2-year follow-up exams in the CRYO-ROP study. Testers were unaware of the retinal status of individual eyes. RESULTS: Measurable scores for both letter and grating acuity were obtained from 1694 eyes at 3 1/2 years and 2101 eyes at 4 1/2 years. Correlation analysis showed that the relation between crowded HOTV and grating acuity scores was best described by a quadratic function, with r2 values of 0.57 at 3 1/2 years and 0.68 at 4 1/2 years. Difference scores were calculated for each eye by subtracting the log of the HOTV score (converted to cyc/deg based on the convention that 20/20 = 30 cyc/deg) from the log TAC score. Normal eyes showed HOTV acuity that was higher than TAC acuity by an average of 0.37 octave (SD = 0.46, n = 1150) at 3 1/2 years and 0.27 octave (SD = 0.43, n = 1337) at 4 1/2 years. HOTV and grating acuity scores were similar to each other in eyes with retinal residua of ROP. Overall, eyes with acuity better than 20/150 to 20/300 tended to show better HOTV than grating acuity, whereas those with acuity below 20/150 to 20/300 generally showed better grating than HOTV acuity. CONCLUSIONS: There is a significant correlation between crowded HOTV letter acuity and TAC grating acuity in young children for normal eyes and eyes with ROP residua. In both groups of eyes, eyes with lower acuity show better grating than letter acuity, whereas eyes with better acuity show slightly higher letter than grating acuity.

Effect of acute-phase retinopathy of prematurity on grating acuity development in the very low birth weight infant. The Cryotherapy for Retinopathy of Prematurity Cooperative Group.

PURPOSE: To examine the development of grating acuity in four groups of eyes in the Multicenter Study of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP): eyes with no ROP; eyes with less-than-prethreshold ROP; eyes with prethreshold ROP; and eyes with threshold ROP that were randomized to serve as controls (not treated with cryotherapy). METHODS: Subjects were 1398 children with birth weights < 1251 g whose acute-phase ROP was documented as part of the CRYO-ROP study. Monocular grating acuity was measured using the Teller acuity card procedure when children reached 1, 2, 3 1/2, and 4 1/2 years of age. RESULTS: Eyes in the no-ROP and less-than-prethreshold groups showed nearly identical acuity development. Eyes with prethreshold ROP showed mean acuity similar to the no-ROP group at 1 and 2 years, but slightly below the no-ROP group at 3 1/2 and 4 1/2 years. Only 50% of eyes in the threshold untreated ROP group had measurable acuity. These eyes showed mean acuity scores that were approximately 1 octave below those of the no-ROP group at all four test ages. When data from eyes with ROP residua or other ocular abnormalities, and data from eyes of children who were unable to pass the study developmental screening items, were excluded, acuity development was similar among groups. CONCLUSIONS: Mild (less-than-prethreshold) ROP has no effect on the development of grating acuity in children between 1 and 4 1/2 years of age. Moderate (prethreshold) ROP is associated with reduced acuity at 3 1/2 and 4 1/2 years. In general, severe (threshold untreated) ROP results in moderate to severe reductions in acuity at all ages between 1 and 4 1/2 years. However, a small number of children with severe ROP show normal acuity development.

Involution of retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVE: To report the timing of involution of acute retinopathy of prematurity (ROP). DESIGN: An analysis of prospective retinal observational data recorded at infants' eye examinations. PARTICIPANTS: Infants from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) had birth weights less than 1251 g and served as subjects. The study population included 766 children who were examined in 5 of the 23 study centers and who developed at least 1 clock hour of acute ROP, stages 1 through 3. One eye from each patient was randomly chosen for analysis. MAIN OUTCOME MEASURES: Investigators documented the location, extent, and severity of ROP during serial retinal examinations. The onset of the ROP's involution was determined from a review of these data, applying a set of predetermined criteria. RESULTS: Acute-phase ROP began to involute at a mean of 38.6 weeks postmenstrual age. In 90% of patients, the ROP began to involute before 44 weeks of postmenstrual age. Acute ROP that demonstrated involution by moving from zone II to zone III was associated with an unfavorable outcome in 2 (1%) of 200 cases. Retinopathy of prematurity that was present only in zone III during a child's serial retinal examinations was never associated with the development of a partial or total retinal detachment. CONCLUSIONS: The onset of involution of acute retinopathy of prematurity correlates better with postmenstrual rather than with chronological age. This is reminiscent of the reported similar correlation of postmenstrual age to the time of onset of prethreshold and threshold ROP. Zone III ROP was nearly always associated with a favorable outcome.

Ocular cosmesis in retinopathy of prematurity. The Cryotherapy for Retinopathy of Prematurity Cooperative Group.

We report the externally apparent outcome in the natural history cohort (n = 4099) that was followed up prospectively in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. The overall incidence of an adverse cosmetic outcome in the survivors who were examined 12 months post term (n = 2759) was 15.1%. Adverse cosmetic outcomes included strabismus (12.8%), nystagmus (3.3%), total retrolental membrane (1%), epiphora (0.6%), corneal opacity (0.6%), cataract (0.3%), and episcleral hyperemia (0.3%). A comparable subgroup examined 24 months post term showed strabismus (14.4%), nystagmus (2.2%), epiphora (0.5%), corneal opacity (0.7%), cataract (0.5%), episcleral hyperemia (0.5%), lid fissure asymmetry (2.4%), and corneal diameter asymmetry (2.0%). The rate of adverse aesthetic outcome was greatest in eyes that had developed more severe acute retinopathy of prematurity and an unfavorable structural outcome. In patients with bilateral threshold retinopathy of prematurity who underwent no therapeutic ocular procedures, other than randomized assignment to undergo cryotherapy in one eye, more frequent adverse cosmetic outcomes were found in the untreated eyes.

Partial retinal detachment at 3 months after threshold retinopathy of prematurity. Long-term structural and functional outcome. Multicenter Trial of Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVE: To investigate the structural and functional outcome at age 4 1/2 years of eyes that had partial retinal detachment (RD) at 3 months after the occurrence of threshold retinopathy of prematurity; these eyes were involved in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity study. METHODS: Of the 531 eyes in the randomized portion of the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity study, 61 had partial RD at the 3-month examination. The extent of retinal involvement was recorded, and the presence of a foveal detachment was noted. At the examination conducted at age 4 1/2 years, the fundus structure was graded into cicatricial retinopathy of prematurity outcome categories by study ophthalmologists, and the visual acuity was measured by masked examiners using the Teller Acuity Card procedure and the crowded HOTV recognition acuity test. RESULTS: Of the 61 eyes, 7 eyes continued to have partial RD at age 4 1/2 years. Of the remaining eyes, 20 eyes had structural outcomes classified as favorable in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity study, and 27 eyes had unfavorable structural outcomes. Data were unrecordable for 3 eyes and missing for 4 eyes. No difference in outcome was found for eyes with partial RD at 3 months that had undergone cryotherapy vs eyes that had served as controls. Only 6 eyes had a visual acuity better than 20/200. When partial RDs did not involve the fovea at 3 months, structural and functional outcomes at 4 1/2 years were better than when RDs involved the fovea. The best predictor of outcome was the extent of RD at 3 months. CONCLUSIONS: Partial RD present 3 months after threshold retinopathy of prematurity is unstable anatomically, and the visual outcome is generally poor. Structure and function at 4 1/2 years are related to the extent of RD and the involvement of the fovea at 3 months.

Photographic grading in the retinopathy of prematurity cryotherapy trial.

We report a system for photographic grading of the posterior fundus features of retinopathy of prematurity and correlation of such features with potential future visual function. The severity of temporal vessel traction, retinal fold, macular ectopia, retinal detachment, retrolental mass, blood vessel attenuation, retinal pigment epithelial scarring, and cataract was assessed by review of photographs at the Fundus Photograph Reading Center, Portland, Ore, according to a scheme designed to avoid bias or knowledge of treatment status. Reliability for all features was in the fair to excellent range (kappa greater than .40), except for blood vessel attenuation (kappa = .18), which was not a factor in the final outcome determination. The grading scheme provided the basis for the 3-month conclusions of the multicenter trial of cryotherapy for retinopathy of prematurity. This system will have further application in the 12-month Cryotherapy for Retinopathy of Prematurity Study conclusions and in future long-term correlation with visual acuity as the trial patients mature.

Grating visual acuity in eyes with retinal residua of retinopathy of prematurity. The Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVES: To compare grating visual acuity of eyes with varying severity of retinal residua of retinopathy of prematurity to grating visual acuity of eyes that did not have acute-phase retinopathy of prematurity, showed no ocular abnormalities on follow-up, and were from patients who passed neurodevelopmental screening questions. DESIGN: Monocular grating visual acuity was measured by means of the Teller acuity card procedure when children reached 1, 2, 3 1/2, and 4 1/2 years of age. PATIENTS: A total of 1398 children with birth weights less than 1251 g whose acute-phase retinopathy of prematurity was documented as part of the Multicenter Cryotherapy for Retinopathy of Prematurity Study and who participated in follow-up visual acuity testing. RESULTS: Eyes with no or mild residua of retinopathy of prematurity showed a mean visual acuity similar to that of the comparison group. Eyes in a subgroup with abnormally straightened temporal retinal vessels showed a mean visual acuity approximately 1 octave below that of the comparison group. Mean visual acuity scores from eyes with macular heterotopia ranged from 1 octave (at 1 year) to more than 2 octaves (at 4 1/2 years) below the mean visual acuity of the comparison group. Mean visual acuity scores for the few eyes in the retinal fold or partial detachment group that had quantifiable visual acuity were well below the means for the comparison group. CONCLUSIONS: Acute-phase retinopathy of prematurity that regresses without retinal residua produces no deficit in grating visual acuity between 1 and 4 1/2 years of age. In contrast, eyes with macular heterotopia show a visual acuity deficit, and the deficit is greater at older than at younger ages. Eyes with retinal fold or partial detachment that have measurable visual acuity show large visual acuity deficits at all ages.

Strabismus in premature infants in the first year of life. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVES: To present the 3- and 12-month strabismus data from 3030 premature infants with birth weights less than 1251 g enrolled in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. DESIGN: Data from the 3- and 12-month examinations conducted at 23 regional study centers were tabulated for all infants. The main outcome measure, ocular motility, was compared with baseline demographic variables and retinopathy of prematurity severity for the worse eye. Findings at 3 months were compared with the incidence of strabismus at 12 months. RESULTS: At 3 months, 200 (6.6%) of the 3030 infants were strabismic. In the 2449 infants examined at both time points, 289 (11.8%) were found to have strabismus at 12 months. Retinopathy of prematurity was significant for strabismus at both 3 and 12 months (P<.001). The presence of strabismus at 3 months was found to be a highly significant predictor of strabismus at 12 months. Anisometropia, abnormal fixation, and unfavorable retinal structure also were significant predictors of strabismus at 1 year. The total prevalence of strabismus in the first year of life was 14.7%. CONCLUSION: The presence of acute-phase retinopathy of prematurity places the premature infant at increased risk for strabismus.

Early retinal vessel development and iris vessel dilatation as factors in retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) Cooperative Group.

OBJECTIVE: To determine whether the extent of retinal vessel development present on early screening examinations for retinopathy of prematurity has prognostic value? DESIGN: The prospectively collected data from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity were used to compare the development of acute retinopathy of prematurity and long-term structural and visual outcomes for eyes with differing extents of retinal vessel development. PATIENT: Study patients had eyes with the following vessel development. In zone I eyes, vessels extended from the disc less than twice the distance from the disc to the macula. In zone II eyes, vessels extended beyond zone I but not to the nasal ora serrata. Transitional eyes had vessels partly in zone I and partly in zone II. RESULTS: The chance of developing threshold retinopathy of prematurity was inversely related to the early degree of vessel development: 54% for zone I eyes, 25% for transitional eyes, and 8% for zone II eyes. The presence of prominent iris vessels at 34 to 35 weeks of postmenstrual age was associated with increased risk for all three groups; zone I eyes almost always needed treatment (94%). The chance of having an unfavorable anatomic alteration of the posterior fundus, or poor vision at the ages of 1 year and 3 1/2 years, was also inversely related to the degree of early vessel development. Vessel development was an independently important factor even when birth weight, gestational age, and race were considered. CONCLUSIONS: The degree of early retinal vessel development is a significant predictor of outcome from retinopathy of prematurity. Iris vessel dilatation is an important indication for greater vigilance in following these infants.

Endogenous Candida endophthalmitis in infants.

Two infants recovered from endogenous Candida endophthalmitis. Case 1, to the best of my knowledge, is the first reported full term neonate with this entity. Free-floating vitreous opacitis ("ballon vitréen") were found in one infant and the second infant's lesions resolved in a more conventional manner.

The relationship between fixation disparity and heterophoria.

Twenty-five asymptomatic subjects with normal binocular vision underwent determination of the magnitude and direction of their heterophoria and their fixation disparity. Fixation disparity was measured at a 2-m fixation distance with the phase-difference haploscope under conditions simulating those of casual seeing. When combined with careful attention to symmetrical control of accommodation, this method eliminates several known technical artifacts. Examples of the normal fluctuation of the magnitude and direction of fixation disparity for individual subjects were demonstrated. Whereas only a slight preponderance of subjects were esophoric, many subjects had convergent fixation disparity (esodisparity). Linear regression analysis of the data revealed a coefficient of correlation between fixation disparity and heterophoria at 6 m of 0.61, and at 33 cm of 0.50. The results suggest that normal, small magnitude heterophoria does not necessarily produce fixation disparity and that fixation disparity does not necessarily sustain heterophoria.

Outcome-based management of retinopathy of prematurity. Multicenter Trial of Cryotherapy for Retinopathy of prematurity Cooperative Group.

PURPOSE: A system is presented for sequentially computing the risk of progression of retinopathy of prematurity (ROP) for infants born weighing not more than 1250 gm. A personal computer program is used to monitor infants' risk of threshold ROP from first appearance of ROP, and the progression in severity is tracked with multiple logistic risk models developed from data in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. METHODS: After entry of the infant's birth weight, gestational age, ethnicity, birth in the current hospital or elsewhere, single or multiple birth, and maturity zone of retinal vessels, risk of progression to threshold severity is calculated. New estimates of risk are computed at onset of ROP and prethreshold ROP (any zone I ROP, zone II stage 2+ or 3) according to the extent of retinal vascularization when ROP first appears, how rapidly ROP progresses, and how severe it is. When threshold ROP (8 total or 5 contiguous clock hours of stage 3+ in zone I or II) is reached,the system provides separate estimates of risk that the eye will have an unfavorable 3-month outcome if treated or not. RESULTS: Estimates of risk of progression to threshold disease among the 4099 patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity natural history study varied from less than 1% to more than 70%. For eyes with threshold disease, the risk of an unfavorable outcome at 3 months without treatment varied from less than 10% to more than 90%. CONCLUSION: This method of tracking identifies infants at high risk for severe ROP and poor structural outcome. It provides information about prognosis with a specificity heretofore impossible.

Family caregiver experiences with asthma in school-age children.

PURPOSE: To examine family caregiver perspectives and experiences of having a school-age child with asthma. METHOD: Semistructured interview with caregivers of children 6-11 years of age using a grounded theory approach. FINDINGS: A theory of the process of becoming a vigilant caregiver was generated. The process of vigilance is three-fold, consisting of a diagnosis phase followed by a battling phase and finally a resolution phase that uses various strategies to minimize the impact of asthma on the child and family. CONCLUSIONS: This theory of vigilance is useful for health care workers seeking to understand families' experiences with asthma. Knowledge of families in the process of becoming vigilant may assist nurses in developing and planning interventions to improve the quality of care.