Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Approach to initial management of canine generalised epileptic seizures in primary-care veterinary practices in the United Kingdom

OBJECTIVES

To investigate how primary care clinicians in the UK approach initial management of canine generalised epileptic seizures, including factors potentially associated with prescription and choice of anti-seizure drugs (ASDs).

MATERIALS AND METHODS

Electronic health records concerning 3,150,713 consultations (917,373 dogs) were collected from 224 veterinary practices by the Small Animal Veterinary Surveillance Network. Free-text clinical narratives were reviewed to identify those consistent with generalised epileptic seizure activity, including only those recording the first presentation for seizures. Dogs older than 6 years were excluded.

RESULTS

Five hundred and seventeen cases were included. Sixty-seven dogs (13.0%) received anti-seizure drugs at first presentation; this was significantly more likely in dogs presented with cluster seizures (CS) (odds ratio 13.8, 95% confidence interval 7.3 to 26.1). Phenobarbital (n=36) and imepitoin (n=29) were the most frequently chosen anti-seizure drugs. Presentation for a single epileptic seizure occurred in 321 dogs; seven were prescribed anti-seizure drugs. Eighty-six dogs were presented with cluster seizures; 38 were prescribed anti-seizure drugs, most frequently imepitoin (n= 19) and phenobarbital (n=17). Of the dogs presenting with a single seizure and at least 6-month follow-up (n=165), 33 (20%) did not have subsequent seizures recorded.

CLINICAL SIGNIFICANCE

Primary care clinicians rarely prescribed anti-seizure drugs following a single epileptic seizure in accordance with International Veterinary Epilepsy Task Force recommendations. Less than half of dogs initially presenting with cluster seizures were prescribed anti-seizure drugs. Imepitoin was frequently selected in the treatment of cluster seizures despite no authorisation for this purpose. These findings may ultimately contribute to improved cohesion in the management of canine epileptic seizures between primary care and referral institutions.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

DNA dosimeter measurements of beam profile using a novel simultaneous processing technique

A DNA dosimeter (DNAd) was previously developed that uses double-strand breaks (DSB) to measure dose. This dosimeter has been tested to measure dose in scenarios where transient-charged particle equilibrium (TCPE) has been established. The probability of double strand break (PDSB_o), which is the ratio of broken double-stranded DNA (dsDNA) to the initial unbroken dsDNA in the dosimeter, was used to quantify DSBs and related to dose. The goal of this work is to produce a new technique to process and analyze the DNAd and quantify DNA-DSBs. This technique included simultaneously processing multiple DNAds and also establishing a new form to the probability of double strand break (PDSB_n), which was then used to test the DNAd in a non-TCPE condition by taking beam penumbra measurements. The technique utilized a 384-well plate, and the measurements were made at the edge of a 10 × 10 cm field and compared to film measurements. During these penumbra measurements, while observing the positional differences in the higher gradient region at 4.1 and 4.55 cm from the center of the radiation field, the distance to agreement of PDSB_o to film were 0.38 cm and 0.26 cm while the distance to agreement of PDSB_n to film were 0.11 cm and 0.06 cm, respectively. Finally, the developed new separation technique reduced the time needed for the analysis of 25 samples from 200 min to 30 min.

Optimizing the response, precision, and cost of a DNA double-strand break dosimeter

We developed a dosimeter that measures biological damage following delivery of therapeutic beams in the form of double-strand breaks (DSBs) to DNA. The dosimeter contains DNA strands that are labeled on one end with biotin and on the other with fluorescein and attached to magnetic microbeads. Following irradiation, a magnet is used to separate broken from unbroken DNA strands. Then, fluorescence is utilized to measure the relative amount of broken DNA and determine the probability for DSB. The long-term goal for this research is to evaluate whether this type of biologically based dosimeter holds any advantages over the conventional techniques. The purpose of this work was to optimize the dosimeter fabrication and usage to enable higher precision for the long-term research goal. More specifically, the goal was to optimize the DNA dosimeter using three metrics: the response, precision, and cost per dosimeter. Six aspects of the dosimeter fabrication and usage were varied and evaluated for their effect on the metrics: (1) the type of magnetic microbeads, (2) the microbead to DNA mass ratio at attachment, (3) the type of suspension buffer used during irradiation, (4) the concentration of the DNA dosimeter during irradiation, (5) the time waited between fabrication and irradiation of the dosimeter, and (6) the time waited between irradiation and read out of the response. In brief, the best results were achieved with the dosimeter when attaching 4.2 µg of DNA with 1 mg of MyOne T1 microbeads and by suspending the microbead-connected DNA strands with 200 µl of phosphate-buffered saline for irradiation. Also, better results were achieved when waiting a day after fabrication before irradiating the dosimeter and also waiting an hour after irradiation to measure the response. This manuscript is meant to serve as guide for others who would like to replicate this DNA dose measurement technique.

Mifamurtide in osteosarcoma--a practical review

Mifamurtide, also known as liposomal muramyl tripeptide phosphatidyl ethanolamine (L-MTP-PE), has been approved for the treatment of osteosarcoma in Europe. Mifamurtide's rational drug design employs MTP-PE for macrophage activation in a multilamellar liposome drug carrier, containing the synthetic phospholipids 1-palmitoyl-2-oleoyl phosphatidyl choline (POPC) and 1,2-dioleoyl phosphatidyl serine (OOPS). Although the drug is not cytotoxic towards normal or tumor cells in vitro, immune activation against osteosarcoma lung metastases in vivo accounts for mifamurtide's antiosteosarcoma effects. Phosphatidyl serine-containing lipids signal macrophage cells that have "flipped phosphatidyl serine" to the outer membrane after apoptosis (e.g., after damage of tumor cells from chemotherapy); thus, both mifamurtide's active and inactive ingredients target immune cells in the lungs. Mifamurtide administration has resulted in 8% and 13% improvement in 6- and 5-year overall survivals, when added to chemotherapy in nonmetastatic and metastatic patients with osteosarcoma, respectively. The short-term toxicities of mifamurtide (fever, headache, flu-like symptoms and rigors) are reduced or eliminated using ibuprofen (200 mg) as premedication for the first infusion; an algorithm for pre- and postmedication is presented. To date, no long-term side effects of mifamurtide have been reported. Compassionate access programs based in two major cancer centers (MD Anderson and Memorial Sloan-Kettering), have recently provided this potentially life-saving drug in North America. The experience with mifamurtide provides an outstanding example of successful cooperation among regulatory bodies and agencies, the pharmaceutical industry and pediatric oncologists to improve cancer care and outcomes for children and young people with a rare sarcoma.

Free-energy component analysis of 40 protein-DNA complexes: a consensus view on the thermodynamics of binding at the molecular level

Noncovalent association of proteins to specific target sites on DNA--a process central to gene expression and regulation--has thus far proven to be idiosyncratic and elusive to generalizations on the nature of the driving forces. The spate of structural information on protein--DNA complexes sets the stage for theoretical investigations on the molecular thermodynamics of binding aimed at identifying forces responsible for specific macromolecular recognition. Computation of absolute binding free energies for systems of this complexity transiting from structural information is a stupendous task. Adopting some recent progresses in treating atomic level interactions in proteins and nucleic acids including solvent and salt effects, we have put together an energy component methodology cast in a phenomenological mode and amenable to systematic improvements and developed a computational first atlas of the free energy contributors to binding in approximately 40 protein-DNA complexes representing a variety of structural motifs and functions. Illustrating vividly the compensatory nature of the free energy components contributing to the energetics of recognition for attaining optimal binding, our results highlight unambiguously the roles played by packing, electrostatics including hydrogen bonds, ion and water release (cavitation) in protein-DNA binding. Cavitation and van der Waals contributions without exception favor complexation. The electrostatics is marginally unfavorable in a consensus view. Basic residues on the protein contribute favorably to binding despite the desolvation expense. The electrostatics arising from the acidic and neutral residues proves unfavorable to binding. An enveloping mode of binding to short stretches of DNA makes for a strong unfavorable net electrostatics but a highly favorable van der Waals and cavitation contribution. Thus, noncovalent protein-DNA association is a system-specific fine balancing act of these diverse competing forces. With the advances in computational methods as applied to macromolecular recognition, the challenge now seems to be to correlate the differential (initial vs. final) energetics to substituent effects in drug design and to move from affinity to specificity.

Unilateral left prefrontal transcranial magnetic stimulation (TMS) produces intensity-dependent bilateral effects as measured by interleaved BOLD fMRI

Transcranial magnetic stimulation (TMS) administered over the prefrontal cortex has been shown to subtly influence neuropsychological tasks, and has antidepressant effects when applied daily for several weeks. Prefrontal TMS does not, however, produce an immediate easily observable effect, making it hard to determine if one has stimulated the cortex. Most prefrontal TMS studies have stimulated using intensity relative to the more easily determined motor threshold (MT) over motor cortex. Five healthy adults were studied in a 1.5 T MRI scanner during short trains of 1 Hz TMS delivered with a figure eight MR compatible TMS coil followed by rest epochs. In a randomized manner, left prefrontal TMS was delivered at 80%, 100% and 120% of MT interleaved with BOLD fMRI acquisition. Compared to rest, all TMS epochs activated auditory cortex, with 80% MT having no other areas of significant activation. 100% MT showed contralateral activation and 120% MT showed bilateral prefrontal activation. Higher intensity TMS, compared to lower, in general produced more activity both under the coil and contralaterally. Higher prefrontal TMS stimulation intensity produces greater local and contralateral activation. Importantly, unilateral prefrontal TMS produces bilateral effects, and TMS at 80% MT produces only minimal prefrontal cortex activation.

Safety of CO(2)- and gadodiamide-enhanced angiography for the evaluation and percutaneous treatment of renal artery stenosis in patients with chronic renal insufficiency

OBJECTIVE

The objective of our study was to evaluate the safety of CO(2) and gadodiamide angiography for diagnosing and percutaneously treating renal artery stenosis in patients with chronic renal insufficiency and presumed ischemic nephropathy.

SUBJECTS AND METHODS

One hundred forty-six consecutive patients with chronic renal insufficiency (serum creatinine > 1.5 mg/dL) were examined for renal artery stenosis using CO(2) and gadodiamide as the angiographic contrast agents. If renal artery stenosis was detected, percutaneous balloon angioplasty with or without stenting was performed. In patients for whom 48-hr creatinine levels were available, we performed an analysis to determine the incidence of contrast-involved nephropathy (increase in serum creatinine of 0.5 mg/dL at 48 hr without identifiable cause). Major complications were reported up to 1 week, and mortality was reported up to 30 days after the procedure.

RESULTS

Ninety-five patients had serum creatinine levels available at 48 hr. An increase in creatinine of greater than 0.5 mg/dL at 48 hr occurred in three patients (3.2%), presumably caused by CO(2), by gadodiamide, or by both. Neither diabetes nor the degree of preexisting chronic renal insufficiency was a predictor of worsening renal function 48 hr after the procedure. The volumes of CO(2) and gadodiamide used for diagnostic studies alone versus the volume used for interventional studies was not significantly different (for CO(2), p = 0.09; for gadodiamide, p = 0.30). Eleven major complications occurred in eight patients (5.5%). Two deaths (1.4%) occurred within 30 days. One death was due to cholesterol embolization and the other was not believed to be related to the procedure.

CONCLUSION

Angiography and percutaneous treatment of renal artery stenosis in patients with chronic renal insufficiency and suspected ischemic nephropathy can be performed relatively safely using CO(2) and gadodiamide as angiographic contrast agents without an increased risk of complications. Contrast-induced nephropathy potentially occurred in 3.2% of patients. Neither the degree of underlying renal insufficiency nor diabetes was a risk factor for predicting a greater likelihood of renal function worsening at 48 hr of follow-up. The volumes of CO(2) and gadodiamide used in this study did not result in an increased risk of contrast-involved nephropathy.

Classifying complex pediatric feeding disorders

BACKGROUND

This study defines the multiple characteristics associated with complex pediatric feeding problems and determines the relative frequency of each classification in a population referred to an interdisciplinary feeding team.

METHODS

The written reports from team evaluations on 103 children (64 males, 39 females; age range 4 months to 17 years) were reviewed. Prematurity and/or presence of developmental delay was coded. Identified factors related to current feeding problems were coded according to five categories: structural abnormalities, neurological conditions, behavioral issues, cardiorespiratory problems, metabolic dysfunction.

RESULTS

Interrater reliability for the classification coding was 88%. Thirty-eight percent of the children had a history of pre- maturity and 74% were reported to have evidence of developmental delay. The following five categories or combinations were coded most frequently: structural-neurological-behavioral (30%), neurological-behavioral (27%), behavioral (12%), structural-behavioral (9%), and structural-neurological (8%). Overall, behavioral issues were coded more often (85%) than neurological conditions (73%), structural abnormalities (57%), cardiorespiratory problems (7%), or metabolic dysfunction (5%).

CONCLUSIONS

Data analysis using this classification system revealed that the majority of children in this sample had a behavioral component to their complex feeding problem, regardless of concurrent physical factors. These findings suggest that complex pediatric feeding problems are biobehavioral conditions in which biological and behavioral aspects mutually interact, and both need to be addressed to achieve normal feeding.

Decreased pulmonary compliance is an early indicator of pulmonary oxygen injury

Pulmonary oxygen injury is classified by the development of tissue and alveolar edema, surfactant dysfunction, lung inflammation, and decreased pulmonary compliance. In neonates prolonged oxygen therapy is associated with the development of bronchopulmonary dysplasia. Recombinant DNA technology makes it possible to experimentally explore the role of specific proteins in the development of pulmonary oxygen injury. However, in vivo experiments require sensitive ways of identifying pulmonary oxygen injury early in its development. We therefore compared the sensitivities of several experimental assays used to assess pulmonary injury. We found that changes in pulmonary compliance were the most sensitive and showed significant differences after 72 hr of exposure to normobaric hyperoxia (FiO2 = 0.95), which correlated with a small change in the histology of the mice lungs. The concentration of protein in the bronchoalveolar lavage fluid was less sensitive and did not differ significantly until after 96 hr of exposure. The survival in hyperoxia also did not worsen until after 96 hr. The lung wet/ dry weight ratios was the least sensitive assay and did not increase until after 5 days of exposure to normobaric hyperoxia. We conclude that a decrease in pulmonary compliance is an early indicator of pulmonary oxygen injury and may be a better way to study the mechanisms and mediators of pulmonary oxygen injury.

Expression of human immunodeficiency virus type I tat results in down-regulation of bcl-2 and induction of apoptosis in hematopoietic cells

Infection by human immunodeficiency virus type 1 (HIV-1) is characterized by progressive loss of various cell types, mainly CD4+ T lymphocytes. While a passive role for the virus in cell destruction is recognized, it does not account for the vast amount of cell death including those of uninfected "bystander' cells. Since in the past we and others have demonstrated the capacity of the Tat protein of HIV-1 to modulate the expression of various cellular genes and that Tat secreted by HIV-infected cells can be readily taken up by various cell types, we have investigated the role of Tat on inducing apoptosis. Our results indicate that T lymphocytes transfected to constitutively express HIV-1 tat, when grown under serum-free conditions results in rapid apoptosis characterized by typical ultrastructural features and DNA fragmentation. Additionally, we observed that in several hematopoietic cell types, including T and B lymphoid cells and monocytoid cells, the expression of HIV-1 tat results in down-regulation of bcl-2, an oncogene with known potential for inhibition of apoptosis. The tat-mediated down-regulation of bcl-2 was observed at both the transcriptional and translational levels. Also, tat-transfected cells expressed increased amounts of bax, a bcl-2 family protein known to induce apoptosis. While these results support reports in the literature of an active role for tat in inducing cell death in HIV-infected individuals, they point to a new mechanism involving Tat-mediated modulation of bcl-2 and bax.

The DNA-dependent protein kinase: a matter of life and (cell) death

The catalytic subunit of the DNA-dependent protein kinase (DNA-PK) is a member of the phosphatidylinositol 3-kinase family. Recent genetic and biochemical studies indicate the involvement of DNA-PK in immunoglobulin/T-cell-receptor gene recombination, double-strand DNA break repair, the stress response and autoimmunity. A role in the suppression of apoptosis could link some of the enzyme's diverse functions.

Bcl-2 expression in chronic lymphocytic leukemia and its correlation with the induction of apoptosis and clinical outcome

Transcriptional deregulation of the Bcl-2 gene has been demonstrated to extend cell viability via an inhibition of apoptotic cell death. Chronic lymphocytic leukemia (CLL) cells are inherently susceptible to apoptosis during short-term culture. Because increased expression of the Bcl-2 gene has been reported in CLL, we sought to correlate Bcl-2 protein expression with the in vitro propensity towards apoptosis and also clinical outcome. Immunoblot analysis of Bcl-2 protein revealed interpatient variability with nine of 42 (21%) cases demonstrating similar or greater expression than a t(14;18) containing lymphoma cell line and 18 of 42 (43%) cases demonstrating a level of expression similar to or less than that seen in normal peripheral blood lymphocytes. Bcl-2 expression did not correlate with clinical features, or with apoptosis, as measured by an in vitro DNA fragmentation assay. However, analysis of survival in the 33 untreated patients revealed significant differences based on the level of Bcl-2 expression, with higher expression being an adverse feature (P<0.02). This data suggests that Bcl-2 is important in the pathogenesis and progression of CLL and that quantitation of Bcl-2 protein may provide useful prognostic information.

Combination adriamycin and suramin induces apoptosis in bcl-2 expressing prostate carcinoma cells

Bcl-2 expression has been associated with progression of prostate cancer from androgen-dependence to androgen-independence and may contribute to the relative drug-resistant phenotype typically observed in androgen-independent prostate cancer. Dunning-G rat prostate cancer cells transfected with a bcl-2 expression vector demonstrated resistance to apoptosis induced by adriamycin and, to a lesser extent, suramin. Use of adriamycin and suramin in combination, however, circumvents this bcl-2 associated drug resistance. Our findings indicate that combination drug actions may induce apoptosis in resistant malignant cell types with defective apoptotic pathways.

Community health nursing--shelter from the storm

The East Coast experienced a debilitating storm just before Christmas 1992. Nurses went above and beyond the call of duty to care for their community; from their exemplary work, one agency developed a policy to prepare the entire community so that the next disaster won't be a disaster.

The bcl-2 oncogene: apoptosis and neoplasia

Cloning of the t(14;18) translocation breakpoint resulted in the identification of a new putative oncogene, which mapped to 18q21, termed bcl-2. The t(14;18) resulted in inappropriately high levels of bcl-2 expression in follicular lymphoma. Prospective studies using mice transgenic for a human bcl-2-immunoglobulin minigene, intended to recreate the molecular features of the t(14;18), demonstrated that bcl-2 gene deregulation was oncogenic. Interestingly, overexpression of bcl-2 showed no demonstrable influence on rates of cellular proliferation. Rather, bcl-2 was found to extend cellular viability by blocking apoptosis. Recent studies with other oncogenes and tumor suppressor genes, such as c-myc and p53, have demonstrated that the deregulation of apoptosis may be of general significance in the development of multiple types of cancer and appears to be a critical event during multistep carcinogenesis. The selective induction of apoptosis in tumor cell populations is now being considered in the design of novel therapeutic interventions.

Neighborhood nursing--the community as partner

Neighborhood nursing seeks to make community health nursing activities more far reaching than those currently reimbursed by third parties, focusing on the issues of health promotion and disease prevention as significantly as the industry has focused on the acute care provision in home care. Yet variables in community nursing have changed what was the traditional focus of community health nursing practice. One agency is developing a program that will allow delivery of a different type of community health nursing. The outcome is a much richer delivery of care.

Effect of dietary intake on pattern of growth of dominant follicles during the oestrous cycle in beef heifers

Friesian x Hereford heifers (n = 19; mean +/- s.e.m. body weight (BW) = 375 +/- 5 kg) were used in a randomized incomplete block design. Heifers were fed 0.7 (n = 7; L), 1.1 (n = 7; M) or 1.8% (n = 5; G) of BW in dry matter (DM)/day for 10 weeks. Ovaries were examined by ultrasound, for one oestrous cycle, from week 5 of treatment. Maximum diameter of dominant follicles was smaller (P less than 0.05) in L (11.8 +/- 0.1 mm) than in M (13.7 +/- 0.2 mm) or G (13.2 +/- 0.3 mm) heifers. Growth rate (mm/day) of dominant follicles during the oestrous cycle was not affected (P greater than 0.05) by dietary intake. Persistence of dominant follicles was shorter (P less than 0.05) in L (9.8 +/- 0.2 days) than in M (11.9 +/- 0.3 days) or G (12.7 +/- 0.4 days) heifers. Three dominant follicles were identified during the oestrous cycle of 5 of 7 L, 3 of 7 M and 1 of 5 G heifers (P less than 0.10); 2 dominant follicles were identified in the remaining heifers (n = 2 of 7, 4 of 7 and 4 of 5, respectively). Length of the luteal phase and luteal-phase concentrations of progesterone were not affected (P greater than 0.05) by treatment. Low dietary intake reduced the diameter and persistence of dominant follicles during the oestrous cycle of beef heifers and tended to increase the proportion of oestrous cycles with 3 dominant follicles.

Evaluation of the ABA-100 procedure for total and direct bilirubin in serum or plasma

We present a modified Evelyn-Malloy method, adapted to the Abbott Biochromatic Analyzer (ABA-100) for the determination of both total and direct bilirubin. It requires less than 25 mul of serum or plasma. At least 50 samples can be assayed per hour with economy of reagent consumption and the precision compares favorably with that for conventional manual methods.