Blocking the VISTA pathway enhances disease progression in (NZB × NZW) F1 female mice.

V-domain Ig suppressor of T-cell activation (VISTA) is a critical negative checkpoint molecule involved in regulating the immune response. Targeting the pathway with an antagonist anti-VISTA antibody designated 13F3 has been shown to enhance disease severity in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. To determine if VISTA plays a role in murine lupus, New Zealand Black × New Zealand White (BWF1) mice were treated with 13F3 or control hamster Ig and disease monitored. Onset of proteinuria was earlier and renal damage more profound in mice treated with 13F3. Cell subset analysis showed an increase of activated splenic T cells and inflammatory splenic myeloid cells, but no effect on B cells, in mice receiving 13F3. Examination of the kidney showed an increase in inflammatory myeloid cell infiltration with 13F3 treatment. This study along with previous EAE data, suggests that interventions that enhance VISTA regulatory activity may be effective for the treatment of autoimmune disease.

Efficacy of on-farm use of ultraviolet light for inactivation of bacteria in milk for calves.

Ultraviolet light is being employed for bacterial inactivation in milk for calves; however, limited evidence is available to support the claim that UV light effectively inactivates bacteria found in milk. Thus, the objective of this observational study was to investigate the efficacy of on-farm UV light treatment in reducing bacteria populations in waste milk used for feeding calves. Samples of nonsaleable milk were collected from 9 Pennsylvania herds, twice daily for 15 d, both before and after UV light treatment (n=60 samples per farm), and analyzed for standard plate count, coliforms, noncoliform, gram-negative bacteria, environmental and contagious streptococci, coagulase-negative staphylococci, Streptococcus agalactiae, Staphylococcus aureus count, and total solids percentage, and log reduction and percentage log reduction were calculated. Data were analyzed using the mixed procedure in SAS. In all bacteria types, samples collected after UV treatment contained significantly fewer bacteria compared with samples collected before UV treatment. Weighted least squares means for log reduction (percentage log reduction) were 1.34 (29%), 1.27 (58%), 1.48 (53%), 1.85 (55%), 1.37 (72%), 1.92 (63%), 1.07 (33%), and 1.67 (82%) for standard plate count, coliforms, noncoliform, gram-negative bacteria, environmental and contagious streptococci, Strep. agalactiae, coagulase-negative staphylococci, and Staph. aureus, respectively. A percentage log reduction greater than 50% was achieved in 6 of 8 bacteria types, and 43 and 94% of samples collected after UV treatment met recommended bacterial standards for milk for feeding calves. Based on these results, UV light treatment may be effective for some, but not all bacteria types found in nonsaleable waste milk. Thus, farmers should take into account the bacteria types that may need to be reduced when considering the purchase of a UV-treatment system.

Neural steroid sensitivity and aggression: comparing individuals of two songbird subspecies.

Hormones coordinate the expression of complex phenotypes and thus may play important roles in evolutionary processes. When populations diverge in hormone-mediated phenotypes, differences may arise via changes in circulating hormones, sensitivity to hormones or both. Determining the relative importance of signal and sensitivity requires consideration of both inter- and intrapopulation variation in hormone levels, hormone sensitivity and phenotype, but such studies are rare, particularly among closely related taxa. We compared males of two subspecies of the dark-eyed junco (Junco hyemalis) for territorial aggression and associations among behaviour, circulating testosterone (T), and gene expression of androgen receptor (AR), aromatase (AROM) and oestrogen receptor α in three behaviourally relevant brain regions. Thus, we examined the degree to which evolution may shape behaviour via changes in plasma T as compared with key sex steroid binding/converting molecules. We found that the white-winged junco (J. h. aikeni) was more aggressive than the smaller, less ornamented Carolina junco (J. h. carolinensis). The subspecies did not differ in circulating testosterone, but did differ significantly in the abundance of AR and AROM mRNA in key areas of the brain. Within populations, both gene expression and circulating T co-varied significantly with individual differences in aggression. Notably, the differences identified between populations were opposite to those predicted by the patterns among individuals within populations. These findings suggest that hormone-phenotype relationships may evolve via multiple pathways, and that changes that have occurred over evolutionary time do not necessarily reflect standing physiological variation on which current evolutionary processes may act.

Neural sensitivity to sex steroids predicts individual differences in aggression: implications for behavioural evolution.

Testosterone (T) regulates many traits related to fitness, including aggression. However, individual variation in aggressiveness does not always relate to circulating T, suggesting that behavioural variation may be more closely related to neural sensitivity to steroids, though this issue remains unresolved. To assess the relative importance of circulating T and neural steroid sensitivity in predicting behaviour, we measured aggressiveness during staged intrusions in free-living male and female dark-eyed juncos (Junco hyemalis). We compared aggressiveness to plasma T levels and to the abundance of androgen receptor (AR), aromatase (AROM) and oestrogen receptor alpha (ORα) mRNA in behaviourally relevant brain areas (avian medial amygdala, hypothalamus and song control regions). We also asked whether patterns of covariation among behaviour and endocrine parameters differed in males and females, anticipating that circulating T may be a better predictor of behaviour in males than in females. We found that circulating T related to aggressiveness only in males, but that gene expression for ORα, AR and AROM covaried with individual differences in aggressiveness in both sexes. These findings are among the first to show that individual variation in neural gene expression for three major sex steroid-processing molecules predicts individual variation in aggressiveness in both sexes in nature. The results have broad implications for our understanding of the mechanisms by which aggressive behaviour may evolve.

Epidemiology of Mycoplasma bovis in Pennsylvania veal calves.

The objective of the study was to estimate the prevalence and incidence of Mycoplasma bovis, a common cause of pneumonia, in veal calves. Using simple random sampling, 252 calves from 4 veal herds located in central Pennsylvania were selected and longitudinally followed for monthly collection of nasal swabs. Bronchial swabs and lung lesions were collected at the slaughterhouse. Nasal, bronchial, and lung lesion swabs were cultured for bacterial respiratory pathogens. Ninety lung lesions were identified, of which 41.1, 1.1, 1.1, 7.8, and 4.4% were culture positive for M. bovis alone, Pasteurella multocida alone, Mannheimia haemolytica alone, M. bovis and P. multocida co-infection, and M. bovis and M. haemolytica co-infection, respectively. The data indicate that potential interventions, such as therapeutics, vaccines, or management control measures, would be most effective before 50 d of age based upon the cumulative incidence of colonization.

Chronic adolescent stress causes sustained impairment of cognitive flexibility and hippocampal synaptic strength in female rats.

Females that experience chronic stress during development, particularly adolescence, are the most vulnerable group to stress-induced disease. While considerable attention has been devoted to stress-induced manifestation of anxiety, depression, and PTSD, evidence indicates that a history of chronic stress is also a risk factor for cognitive decline and dementia - with females again in a higher risk group. This interplay between sex and stress history indicates specific mechanisms drive neural dysfunction across the lifespan. The presence of sex and stress steroid receptors in the hippocampus provides a point of influence for these variables to drive changes in cognitive function. Here, we used a rodent model of chronic adolescent stress (CAS) to determine the extent to which CAS modifies glutamatergic signaling resulting in cognitive dysfunction. Male and female Wistar rats born in-house remained non-stressed (NS), unmanipulated aside from standard cage cleaning, or were exposed to either physical restraint (60 min) or social defeat (CAS) each day (6 trials each), along with social isolation, throughout the adolescent period (PND 35-47). Cognition was assessed in adult (PND 80-130) male and female rats (n = 10-12) using the Barnes Maze task and the Attention Set-Shift task. Whole hippocampi were extracted from a second cohort of male and female rats (NS and CAS; n = 9-10) and processed for RNA sequencing. Brain tissue from the first cohort (n = 6) was processed for density of glutamatergic synaptic markers (GluA1, NMDA1a, and synaptophysin) or whole-cell patch clamping (n = 4) to determine glutamatergic activity in the hippocampus. Females with a history of chronic stress had shorter latencies to locate the goal box than NS controls during acquisition learning but showed an increased latency to locate the new goal box during reversal learning. This reversal deficit persisted across domains as females with a history of stress required more trials to reach criterion during the reversal phases of the Attention Set-Shift task compared to controls. Ovariectomy resulted in greater performance variability overall during reversal learning with CAS females showing worse performance. Males showed no effects of CAS history on learning or memory performance. Bioinformatic prediction using gene ontology categorization indicated that in females, postsynaptic membrane gene clusters, specifically genes related to glutamatergic synapse remodeling, were enriched with a history of stress. Structural analysis indicated that CAS did not alter glutamate receptor density in females. However, functionally, CAS females had a decreased AMPA/NMDA-dependent current ratio compared to controls indicating a weakening in synaptic strength in the hippocampus. Males showed only a slight change in density of NMDA1a labeling in the CA3 region with a history of stress. The data observed here suggest that females are at risk for impaired cognitive flexibility following a history of adolescent stress, possibly driven by changes in glutamatergic signaling.

The CD45 tyrosine phosphatase regulates phosphotyrosine homeostasis and its loss reveals a novel pattern of late T cell receptor-induced Ca2+ oscillations.

CD45 is a transmembrane tyrosine phosphatase implicated in T cell antigen receptor (TCR)-mediated activation. In T cell variants expressing progressively lower levels of CD45 (from normal to undetectable), CD45 expression was inversely related to spontaneous tyrosine phosphorylation of multiple proteins, including the TCR zeta chain, and was directly correlated with TCR-driven phosphoinositide hydrolysis. The Ca2+ response in these cells was altered in an unexpected fashion. Unlike wild-type cells, stimulated CD45- cell populations did not manifest an early increase in intracellular Ca2+, but did exhibit a delayed and gradual increase in mean intracellular Ca2+. Computer-aided fluorescence imaging of individual cells revealed that CD45- cells experienced late Ca2+ oscillations that were not blocked by removal of extracellular Ca2+. CD45 revertants had the signaling properties of wild-type cells. Thus, CD45 has a profound influence on both TCR-mediated signaling and phosphotyrosine homeostasis, and its loss reveals a novel role for this tyrosine phosphatase in Ca2+ regulation.

Glutamate receptor RNA editing in vitro by enzymatic conversion of adenosine to inosine.

RNA encoding the B subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) subtype of ionotropic glutamate receptor (GluR-B) undergoes a posttranscriptional modification in which a genomically encoded adenosine is represented as a guanosine in the GluR-B complementary DNA. In vitro editing of GluR-B RNA transcripts with HeLa cell nuclear extracts was found to result from an activity that converts adenosine to inosine in regions of double-stranded RNA by enzymatic base modification. This activity is consistent with that of a double-stranded RNA-specific adenosine deaminase previously described in Xenopus oocytes and widely distributed in mammalian tissues.

Regulation of TCR signaling by CD45 lacking transmembrane and extracellular domains.

The CD45 protein is a transmembrane tyrosine phosphatase that is required for normal T cell receptor (TCR)-mediated signaling. A chimeric complementary DNA encoding the intracellular enzymatically active portion of murine CD45 preceded by a short amino-terminal sequence from p60c-src was transfected into CD45- T cells. Expression of this chimeric protein corrected most of the TCR signaling abnormalities observed in the absence of CD45, including TCR-mediated enhancement of tyrosine kinase activity and Ca2+ flux. Thus, the enzymatically active intracellular portion of CD45 is sufficient to allow TCR transmembrane signaling.

Changes in weight and waist circumference over 9 years in a Scottish population.

OBJECTIVE: To document patterns of measured weight and waist circumference (WC) change and the increase in overweight and obesity over a 9-year period. SUBJECTS/METHODS: A total of 1044 subjects from two age-defined cohorts aged 39 and 59 in 1991. Height, weight and WC were measured in 1991, 1995 and 2000 and body mass index (BMI) was calculated. Pattern of weight and WC change was studied over approximately 9 years. RESULTS: The prevalence of overweight and obesity increased markedly and the younger cohort showed greater increases in weight and WC than the older cohort. There was no significant difference in mean BMI and/or mean 9-year weight change between men and women in either age cohort, and mean weight gain was similar for all occupational groups. Only 20% of subjects maintained a stable weight (+/-2 kg), while 42.2 and 17.6% gained greater than 5 and 10 kg over the 9-year period, respectively. The rate of weight gain appeared to be relatively steady over the 9 years among younger subjects but declined in the older subjects in the second half of the observation period. CONCLUSIONS: Health promotion strategies to prevent weight gain need to be population-based, targeting all social and age groups, but particularly those in their early middle-age.

Measuring food access in Melbourne: access to healthy and fast foods by car, bus and foot in an urban municipality in Melbourne.

Access to healthy food can be an important determinant of a healthy diet. This paper describes the assessment of access to healthy and unhealthy foods using a GIS accessibility programme in a large outer municipality of Melbourne. Access to a major supermarket was used as a proxy for access to a healthy diet and fast food outlet as proxy for access to unhealthy food. Our results indicated that most (>80%) residents lived within an 8-10 min car journey of a major supermarket i.e. have good access to a healthy diet. However, more advantaged areas had closer access to supermarkets, conversely less advantaged areas had closer access to fast food outlets. These findings have application for urban planners, public health practitioners and policy makers.

Residues in the RNP1-like sequence motif of Rho protein are involved in RNA-binding affinity and discrimination.

The termination of transcription in Escherichia coli by action of Rho factor is dependent on the ability of this homohexameric protein to make productive interactions with the nascent RNA molecule to be terminated. The roles of two residues in a phylogenetically conserved sequence motif in the RNA-binding domain of Rho, Asp60 and Phe62, were analyzed by studies of the biochemical properties of pure mutant proteins. F62S Rho had greatly reduced affinity for lambda cro RNA, very poor ability to terminate transcription in vitro by itself and only partial termination activity (at a level consistent with its in vivo defect) in the presence of NusG. D60G Rho had a high affinity for lambda cro RNA but a much lower ability to discriminate against RNA molecules lacking cis-acting Rho-utilization sequences, and a reduced efficiency of termination that was not improved by NusG. These results indicate a major role for Phe62 in stabilizing the binding of Rho to RNA through hydrophobic interactions, while Asp60 provides an electrostatic repulsive force that allows a rapid dissociation of non-productive complexes with RNA.

Combinatorial effects of NusA and NusG on transcription elongation and Rho-dependent termination in Escherichia coli.

The transcription factors NusA and NusG from Escherichia coli are modulators of the RNA polymerase elongation reaction and Rho-dependent transcription termination. NusA decreases the elongation rate and termination efficiency while NusG increases both activities. Both Nus factors are able to physically interact with Rho and with RNA polymerase. Experiments with purified components designed to determine whether these factors act independently or competitively showed that the change in elongation rate was a composite of their individual effects, that the combined effect on termination was dependent on the reaction conditions and that the two factors do not compete for their sites of action for either effect. The two factors were also found not to enhance significantly the slight (20%) inhibition of elongation caused by 200 microM guanosine 3',5'-bisdiphosphate (ppGpp) during transcription in vitro. The results also show that the effects of NusA and NusG on RNA polymerase elongation and Rho function are contrary to the inverse relationship between elongation and termination that is expected for a kinetic coupling of Rho action to RNA polymerase elongation. This property suggests that in addition to their known actions on RNA polymerase that influence the length of pausing, these factors act on some other rate-limiting step of the Rho-dependent termination process.

The nucleoid-associated protein StpA binds curved DNA, has a greater DNA-binding affinity than H-NS and is present in significant levels in hns mutants.

The StpA protein is closely related to H-NS, the well-characterised global regulator of gene expression which is a major component of eubacterial chromatin. Despite sharing a very high degree of sequence identify and having biochemical properties in common with H-NS, the physiological function of StpA remains unknown. We show that StpA exhibits similar DNA-binding activities to H-NS. Although both display a strong preference for binding to curved DNA, StpA binds DNA with a four-fold higher affinity than H-NS, with K(d)s of 0.7 microM and 2.8 microM, respectively. It has previously been reported that expression of stpA is derepressed in an hns mutant. We have quantified the amount of StpA protein produced under this condition and find it to be only one-tenth the level of H-NS protein in wild-type cells. Our findings explain why the presence of StpA does not compensate for the lack of H-NS in an hns mutant, and why the characteristic pleiotropic hns mutant phenotype is observed.

Anticonvulsant activity of novel derivatives of 2- and 3-piperidinecarboxylic acid in mice and rats.

The relative ability of derivatives of 2-piperidinecarboxylic acid (2-PC; pipecolic acid) and 3-piperidinecarboxylic acid (3-PC; nipecotic acid) to block maximal electroshock (MES)-induced seizures, elevate the threshold for electroshock-induced seizures and be neurotoxic in mice was investigated. Protective index (PI) values, based on the MES test and rotorod performance, ranged from 1.3 to 4.5 for 2-PC benzylamides and from < 1 to > 7.2 for 3-PC derivatives. PI values based on elevation of threshold for electroshock-induced seizures and rotorod performance ranged from > 1.6 to > 20 for both types of derivatives. Since preliminary data indicated that benzylamide derivatives of 2-PC displace [3H]1-[1-(2-thienyl)-cyclohexyl]piperidine (TCP) binding to the phencyclidine (PCP) site of the N-methyl-D-aspartate (NMDA) receptor in the micromolar range and such low affinity uncompetitive antagonists of the NMDA receptor-associated ionophore have been shown to be effective anticonvulsants with low neurological toxicity, the 2-PC derivatives were evaluated in rat brain homogenates for binding affinity to the PCP site. Although all compounds inhibited [3H]TCP binding, a clear correlation between pharmacological activity and binding affinity was not apparent. Select compounds demonstrated minimal ability to protect against pentylenetetrazol-, 4-aminopyridine- and NMDA-induced seizures in mice. Corneal and amygdala kindled rats exhibited different sensitivities to both valproic acid and the nonsubstituted 2-PC benzylamide, suggesting a difference in these two models. Enantiomers of the alpha-methyl substituted benzylamide of 2-PC showed some ability to reduce seizure severity in amygdala kindled rats.

Effects of providing comprehensive ambulatory services to children with chronic conditions.

OBJECTIVE: To document the effects of a comprehensive program of care on the resource utilization and cost of care for children with chronic conditions. DESIGN: Descriptive study of 10715 admissions between 1984 and 1995 with analyses of costs based on charges. Comparisons were made with data from a national consortium of academic medical centers and from a national survey of hospitals. A 2-week survey of staff was conducted to identify their use of time in the care of these patients. PATIENTS: Children aged birth through 18 years meeting International Classification of Diseases, Ninth Revision, Clinical Modification criteria for chronic conditions. Patients with acute conditions were used as controls. INTERVENTION: A program of expanded care funded since 1989 by a regional insurance company. RESULTS: Between 1984 and 1995, mean length of stay for children with chronic conditions decreased from 83.9 to 10.6 days; mean annual admissions decreased from 2796 to 1622. Median hospital inpatient charges, adjusted for cost of living, decreased from $26.1 to $14.6 million. A $77.7 million savings occurred for inpatient care, with total expenditures from the insurance program of $3.6 million (a 21:1 ratio). Almost half the professional activities provided for these children were for services that could not be reimbursed in a fee-for-service model. Median adjusted inpatient charges were lower in Rochester, NY ($8746) than in other academic medical centers ($12773) or in a national survey of hospitals ($12462), and fewer children were readmitted within 30 days in Rochester (12.7%) than in other academic medical centers (15.0%). CONCLUSIONS: An investment of funds by a regional insurance company was associated with reduced costs, admissions, and lengths of stay for children with chronic conditions, and resulted in significant savings for the company. This model may be applicable to other centers.

Nursing care in electroconvulsive therapy.

Psychiatric nursing care for the electroconvulsive therapy (ECT) patient has evolved from a traditional supportive and adjunctive practice to the current practice of independent and collaborative nursing actions. The nurse's multifaceted role is enacted by providing education and support, performing pretreatment assessments, monitoring the procedure, and observing and interpreting posttreatment patient responses. Areas of future nursing education and research should include the expansion of nursing practice with the ECT patient in the provision of quality nursing care.

Very low calorie diet (VLCD): a useful alternative in the treatment of the obese NIDDM patient.

Conventional treatment of obese noninsulin dependent diabetes mellitus (NIDDM) patients is often unsatisfactory. In this study the efficacy of Modifast, a commercial very low calorie diet (VLCD), was evaluated in a population of obese poorly controlled NIDDM patients. The mechanisms of action of VLCD in these patients were also studied by comparing: (i) Plasma insulin and glucose profiles after a VLCD and an isocaloric mixed meal and (ii) plasma amino acid levels, both at baseline and after four weeks of VLCD treatment. A total of 14 obese NIDDM patients (M/F 7/7. median body mass index (BMI) 38.7 kg-2, interquartile range (IQ) 34.7-46.5 kg-2, waist circumference 116 cm, IQ 106-139 cm, insulin treated 7/14) with poor diabetic control (HbA1c 8.6%, IQ 7.8-10%) were studied. Patients were given a VLCD (425 kcal/day) for 12 weeks. At baseline, VLCD and isocaloric meal tests were performed on consecutive mornings. Fasting plasma amino acid levels were also determined at baseline and after 4 weeks of VLCD treatment. Weight, waist circumference, HbA1c, blood pressure, fasting plasma insulin, total cholesterol and triglyceride levels all fell significantly following VLCD treatment. Insulin therapy was able to be ceased in the seven insulin treated patients. Oral hypoglycaemic agent dosage fell from a median of eight (IQ 6-12) to two (IQ 0-8) tablets per day (P = 0.03) in patients initially on this form of therapy. Insulin secretion was higher after VLCD than isocaloric meal (P = 0.04). Fasting plasma alanine level fell from 512.0 (IQ 412.0-563.0) to 374.0 (IQ 342-472.0) mumol/l (P = 0.04) following VLCD treatment. In conclusion, the short term use of a VLCD is very effective in rapidly improving glycaemic control and promoting substantial weight loss in obese NIDDM patients. Moreover, a VLCD diet increases insulin secretion and reduces substrate for gluconeogenesis. Thus, VLCD treatment may improve glycaemic control by factors more than caloric restriction alone.

Modeling a medical environment: an ontology for integrated medical informatics design.

Modern medical environments have seen an increase in technological complexity and pressures of handling more patients with fewer resources, resulting in higher demands on medical practitioners. Medical informatics designers will have to focus on the problem of organizing medical information more effectively to enable practitioners to cope with these challenges. This article addresses this research problem for the particular area of medical problem solving in patient care. First, we describe a traditional modeling approach for medical reasoning used as a basis for developing some decision support systems. We argue these models may be faithful to what is known about biomedical knowledge, but they have limitations for human problem solving, especially in unanticipated situations. Second, we present an ontological framework, known as the abstraction hierarchy (Rasmussen, IEEE Trans. Man. Cybernetics 15 (1985) 234-243), for integrating patient representations that are faithful to existing biomedical knowledge and that are consistent with what is known about human problem solving. Through an example of a critical event in the operating room, we reveal how this framework can support medical problem solving in unanticipated situations. Third, we show how to use these representations as a frame of reference for mapping medical roles, responsibilities, sensors, and controls in an operating room context. Finally, we provide some insight for medical informatics designers in using this framework to design novel training programs and human-computer displays.

Field trial of four cowside antibiotic-residue screening tests.

Four commercially available screening tests for antibiotic residues in milk were evaluated for their ability to correctly identify the antibiotic status of cows. A field trial, which included 199 cows from 2 herds, was conducted. Sensitivity, specificity, and likelihood ratios for a positive test result were calculated by using the Bacillus stearothermophilus var calidolactis disk assay as the reference test. The relationship of risk factors to the probability of a false-positive result for each screening test was modeled by use of unconditional logistic regression. The risk factors evaluated in these models were loge somatic cell count (scc), intramammary infection, herd, milk appearance, time milk sample frozen before tested, days in lactation, parity, and manufacturer's lot number. The risk factors log(e) scc and intramammary infection were forced into all models. The overall specificities for the 4 tests ranged from 0.78 to 0.95, whereas likelihood ratios for a positive test result ranged from 4.54 to 20.0. When the confounding of cofactors was controlled in the logistic model, there was a positive effect of log(e) scc on the probability of a false-positive result for 3 of the screening tests, that is, for incremental increases in log(e) scc, there was an increasing likelihood for a false-positive result. In some of the tests, parity and intramammary infection also influenced the likelihood of a false-positive result. The goal of cowside testing is to assist in the production of high-quality, antibiotic residue-free milk from dairies.(ABSTRACT TRUNCATED AT 250 WORDS)