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.

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.

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.

A yeast expression vector and leucine selection in Escherichia coli to aid in the identification of novel genes.

The complete sequencing of the Saccharomyces cerevisiae genome provides a powerful tool for studying and elucidating essential cellular processes. To aid in the application of this resource to investigations into the molecular mechanisms of endoplasmic reticulum-associated protein degradation, a simple procedure was designed to generate a unique 2-microm LEU2-selectable yeast expression vector. Putative genes easily inserted into this vector are under control of the ADH1 promoter and transcription terminator sequences. Furthermore, a LEU2 selection in both yeast and Escherichia coli was used to allow the isolation of underrepresented plasmid from a pool of multiple vectors. Together, these advances in technology will be useful in the systematic analysis of novel yeast gene function.

Does cryotherapy affect refractive error? Results from treated versus control eyes in the cryotherapy for retinopathy of prematurity trial.

PURPOSE: To evaluate the effect of cryotherapy on refractive error status between ages 3 months and 10 years in children with birth weights of less than 1251 g in whom severe retinopathy of prematurity (ROP) developed in one or both eyes during the neonatal period. DESIGN: Randomized clinical trial. PARTICIPANTS: Two hundred ninety-one children in whom severe ROP developed during the neonatal period. INTERVENTION: Cryotherapy for ROP. MAIN OUTCOME MEASURES: Cycloplegic Refraction METHODS: The children underwent repeated follow-up eye examinations, including cycloplegic retinoscopy, between 3 months and 10 years after term due date. Refractive error data from all eyes that were randomized to cryotherapy were compared with data from all eyes that were randomized to serve as controls. Refractive error data were also compared for a subset of children who had both a treated and a control eye that could be refracted. RESULTS: At all ages, the proportion of treated eyes that were unable to be refracted because of retinal detachment, media opacity, or pupillary miosis was approximately half the proportion of the control eyes that were unable to be refracted. When data from all eyes that could be refracted were considered, the distribution of refractive errors between fewer than 8 diopters (D) of myopia and more than 8 D of hyperopia was similar for treated and control eyes at all ages. The proportion of eyes with 8 D or more of myopia was much higher in treated than in control eyes at all ages after 3 months. In the subset of children who had a treated eye and a control eye that could be refracted, distributions of refractive errors in treated versus control eyes were similar at most ages. CONCLUSIONS: In both treated and control eyes, there was an increase in the prevalence of high myopia between 3 and 12 months of age. Between 12 months and 10 years of age, there was little change in distribution of refractive error in treated or control eyes. The higher prevalence of myopia of 8 D or more in treated eyes, as compared with control eyes, may be the result of cryotherapy's preservation of retinal structure in eyes that, in the absence of cryotherapy, would have progressed to retinal detachment.

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.

Severity of neonatal retinopathy of prematurity is predictive of neurodevelopmental functional outcome at age 5.5 years. Behalf of the Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVE: The purpose of this study was to assess the relation between neonatal retinopathy of prematurity (ROP) in very low birth weight infants and neurodevelopmental function at age 5.5 years. METHODS: Longitudinal follow-up of children occurred in 2 cohorts of the Multicenter Cryotherapy for Retinopathy of Prematurity Study. The extended natural history cohort followed 1199 survivors of <1251 g birth weight from 5 centers. The threshold randomized cohort (ThRz) followed 255 infants <1251 g from 23 centers who developed threshold ROP and who consented to cryotherapy to not more than 1 eye. At 5.5 years both cohorts had ophthalmic and acuity testing and neurodevelopmental functional status determined with the Functional Independence Measure for Children (WeeFIM). RESULTS: Evaluations were completed on 88.7% of the extended natural history cohort; 87% had globally normal functional skills (WeeFIM: >95). As ROP severity increased, rates of severe disability increased from 3.7% among those with no ROP, to 19.7% of those with threshold ROP. Multiple logistic regression analysis demonstrated that better functional status was associated with favorable visual acuity, favorable 2-year neurological score, absence of threshold ROP, having private health insurance, and black race. Evaluations were completed on 87.4% of the ThRz children. In each functional domain, the 134 children with favorable acuity in their better eye had fewer disabilities than did the 82 children with unfavorable acuity: self-care disability 25.4% versus 76.8%, continency disability 4.5% versus 50.0%, motor disability 5.2% versus 42.7%, and communicative-social cognitive disability 22.4% versus 65.9%, respectively. CONCLUSION: Severity of neonatal ROP seems to be a marker for functional disability at age 5. 5 years among very low birth weight survivors. High rates of functional limitations in multiple domains occur in children who had threshold ROP, particularly if they have unfavorable visual acuity.

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.

The incidence of ophthalmologic interventions in children with birth weights less than 1251 grams. Results through 5 1/2 years. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVE: This study aimed to report the frequency of ophthalmologic surgical and medical therapies provided to children with birth weights less than 1251 g who had all stages of retinopathy of prematurity (ROP). In addition, this study aimed to report the initial age at which such procedures are provided and to report the frequency of cerebrospinal fluid shunts. DESIGN: Observational case series with prospective data collection. PARTICIPANTS: Children from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) with birth weights less than 1251 g served as subjects. Group A included 257 children from all 23 CRYO-ROP study centers who had threshold ROP, who had participated in the randomized trial of cryotherapy, and who had survived to age 1 year. Group B included 1208 children from 5 of the 23 study centers who had varying severity of ROP (69 had threshold ROP) and who had participated in a 5 1/2-year study of the natural history of ROP. MAIN OUTCOME MEASURES: Investigators documented medical and surgical ophthalmologic interventions through age 5 1/2 years as well as cerebrospinal fluid shunting surgery for hydrocephalus through age 2 years. RESULTS: Group A was composed of 257 children with threshold ROP who underwent 226 ocular interventions in addition to cryotherapy (0.9 intervention per child). The most common treatments performed on the randomized cohort of children were vitrectomy (26% of patients), lensectomy (18%), amblyopia therapy (20%), and strabismus surgery (10%). Cataract surgery not associated with vitrectomy was performed infrequently (2%) and was performed equally often in treated and control eyes. Amblyopia therapy was prescribed as often for treated as for control eyes. Cerebrospinal fluid shunts were placed in 11% of these children. Group B was composed of 1208 natural history patients who underwent 239 ophthalmologic interventions (0.4 intervention per child). Strabismus surgery was the most commonly performed procedure for the natural history cohort of children (6% of the children). Amblyopia therapy was prescribed for 7% of the natural history patients. Cerebrospinal fluid shunts were required by 3% of the natural history infants, more often in children with more severe ROP. CONCLUSIONS: These premature infants underwent a large number of ophthalmologic treatments during the first 5 1/2 years of life. The long-term costs of both extreme prematurity and ROP include not only the initial ablative therapy for ROP and societal loss due to blindness that still occurs in some cases, but also the ongoing costs of caring for eye problems.

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.

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.

Visual fields measured with double-arc perimetry in eyes with threshold retinopathy of prematurity from the cryotherapy for retinopathy of prematurity trial. The CRYO-Retinopathy of Prematurity Cooperative Group.

PURPOSE: To measure monocular visual field extent in very-low birth weight children in whom severe (threshold) acute-phase retinopathy of prematurity (ROP) developed in one or both eyes, and who had random assignment of eyes to cryotherapy or no cryotherapy. A control group of very-low birth weight children in whom ROP did not develop also was tested. METHODS: There were 78 children in the severe ROP group from 5 of 23 centers in the randomized trial of cryotherapy for ROP (CRYO-ROP). The comparison cohort consisted of 75 study participants in whom ROP did not develop. All subjects had birth weights of less than 1251 g. At the 5 1/2-year study examination, visual field size was measured using double-arc kinetic perimetry. Testers were masked to treatment status of each eye. Four meridia were tested: superotemporal (ST), inferotemporal (IT), inferonasal (IN), and superonasal (SN). Target size was 6 degrees. RESULTS: When blind eyes were assigned a score of 0 degree, the no-ROP, treated, and control eyes had an average visual field extent of 62 degrees, 35 degrees, 27 degrees at ST; 73 degrees, 42 degrees, 35 degrees at IT; 51 degrees, 30 degrees, 21 degrees IN; and 50 degrees, 26 degrees, 22 degrees at SN, respectively. Among 25 children who had bilateral threshold ROP and measurable fields in each eye, values for treated and control eyes were 59 versus 62 at ST, 69 versus 80 at IT, 44 versus 49 at IN, and 41 versus 48 at SN, respectively. CONCLUSIONS: Overall, visual fields in eyes that reached threshold ROP were smaller than those of eyes that did not develop ROP. When only pairs of sighted eyes were considered, visual fields in the treated eyes were 6.4 degrees smaller than those of control eyes. Therefore, it appears that a small loss of peripheral field occurs when cryotherapy prevents the development of retinal detachment.