Osteoarthritis year in review 2022: rehabilitation

This year in review presents key highlights from research relating to osteoarthritis (OA) rehabilitation published from the 1^st April 2021 to the 18^th March 2022. To identify studies for inclusion in the review, an electronic database search was carried out in Medline, Embase and CINAHLplus. Following screening, included studies were grouped according to their predominant topic area, including core OA rehabilitation treatments (education, exercise, weight loss), adjunctive treatments, novel and emerging treatments or research methods, and translation of rehabilitation evidence into practice. Studies of perceived high clinical importance, quality, or controversy in the field were selected for inclusion in the review. Headline findings include: the positive role of technology to support remote delivery of core OA rehabilitation treatments, the importance of delivering educational interventions alongside exercise, the clinical and cost-effectiveness of a stepped approach to exercise, controversy around the potential mechanisms of action of exercise, mixed findings regarding the use of splinting for thumb base OA, increasing research on blood flow restriction training as a potential new intervention for OA, and evidence that the beneficial effects from core OA treatments seen in randomised controlled trials can be seen when implemented in clinical practice. A consistent finding across several recently published systematic reviews is that randomised controlled trials testing OA rehabilitation interventions are often small, with some risk of bias. Whilst future research is warranted, it needs to be large scale and robust, to enable definitive answers to important remaining questions in the field of OA rehabilitation.

The effect of age on specialized palliative care use in the last year of life for patients who die of cancer: A nationwide study from Norway

INTRODUCTION

Specialized palliative care (SPC) is beneficial towards end of life because of its holistic approach to improve quality of life and comfort of patients and their families. Few studies have described how patient age, sex, comorbidities, and socioeconomic status (SES) are associated with SPC use in nonselective populations who die of cancer. This study aimed to evaluate the use of SPC in the year preceding death by all Norwegian individuals with a recent cancer diagnosis who died of cancer.

MATERIALS AND METHODS

From nationwide registries, we identified patients with a recent (<5 years) cancer diagnosis who died during 2010-2014. Using binary logistic regression models, we estimated the probability of receiving hospital-based SPC during the last year of life according to individual (age, sex, comorbidity), cancer (stage, type, and months since diagnosis), and SES (e.g., living alone, household income, and education) characteristics.

RESULTS

The analytical sample contained 45,521 patients with a median age at death of 75 years; 46% were women. The probability of receiving hospital-based SPC in the total cohort was 0.43 (95% confidence interval [CI] 0.42-0.43). Use of SPC was higher if patients were younger, female, had limited comorbidity, metastatic disease, had one the following cancer types: colorectal, pancreatic, bladder, kidney, or gastric, were diagnosed more than six months before death, and had higher SES. Adjusted model results suggested that the probability of using SPC in the last year of life for patients aged 80-89 years was 0.31 (95% CI 0.30-0.32), compared to a probability of 0.63 (95% CI 0.61-0.65) for patients aged 50-59 years. For patients ≥90 years, the probability was 0.16 (95% CI 0.15-0.18).

DISCUSSION

Less hospital-based SPC use among older patients, males, and those with lower SES indicates possible under-treatment in these groups. Future studies should be designed to determine the underlying reasons for these observed differences.

International Foot and Ankle Osteoarthritis Consortium review and research agenda for diagnosis, epidemiology, burden, outcome assessment and treatment

OBJECTIVE

To summarise the available evidence relating to the diagnosis, epidemiology, burden, outcome assessment and treatment of foot and ankle osteoarthritis (OA) and to develop an agenda to guide future research.

METHOD

Members of the International Foot and Ankle Osteoarthritis Consortium compiled a narrative summary of the literature which formed the basis of an interactive discussion at the Osteoarthritis Research Society International World Congress in 2021, during which a list of 24 research agenda items were generated. Following the meeting, delegates were asked to rank the research agenda items on a 0 to 100 visual analogue rating scale (0 = not at all important to 100 = extremely important). Items scoring a mean of 70 or above were selected for inclusion.

RESULTS

Of the 45 delegates who attended the meeting, 31 contributed to the agenda item scoring. Nineteen research agenda items met the required threshold: three related to diagnosis, four to epidemiology, four to burden, three to outcome assessment and five to treatment.

CONCLUSIONS

Key knowledge gaps related to foot and ankle OA were identified, and a comprehensive agenda to guide future research planning was developed. Implementation of this agenda will assist in improving the understanding and clinical management of this common and disabling, yet relatively overlooked condition.

Triggers for acute flare in adults with, or at risk of, knee osteoarthritis: a web-based case-crossover study in community-dwelling adults

OBJECTIVE

To identify proximate causes ('triggers') of flares in adults with, or at risk of, knee osteoarthritis (OA), estimate their course and consequences, and determine higher risk individuals.

METHODS

In this 13-week web-based case-crossover study adults aged ≥40 years, with or without a recorded diagnosis of knee OA, and no inflammatory arthropathy who self-reported a knee flare completed a questionnaire capturing information on exposure to 21 putative activity-related, psychosocial and environmental triggers (hazard period, ≤72 h prior). Comparisons were made with identical exposure measurements at four 4-weekly scheduled time points (non-flare control period) using conditional logistic regression. Flare was defined as a sudden onset of worsening signs and symptoms, sustained for ≥24 h. Flare characteristics, course and consequence were analysed descriptively. Associations between flare frequency and baseline characteristics were estimated using Poisson regression.

RESULTS

Of 744 recruited participants (mean age [SD] 62.1 [10.2] years; 61% female), 376 reported 568 flares (hazards) and provided 867 valid control period measurements. Thirteen exposures (eight activity-related, five psychosocial/environmental) were positively associated with flare onset within 24 h (strongest odds ratio estimate, knee buckling: 9.06: 95% confidence interval [CI] 5.86, 13.99; weakest, cold/damp weather: 1.45: 95%CI 1.12, 1.87). Median flare duration was 5 days (IQR 3, 8), less common if older (incident rate ratio [IRR] 0.98: 95%CI 0.97, 0.99), more common if female (IRR 1.85: 95%CI 1.43, 2.39).

CONCLUSIONS

Multiple activity-related, psychosocial and environmental exposures are implicated in triggering flares. This evidence can help inform prevention and acute symptom management for patients and clinicians.

Partial budget analysis of culture- and algorithm-guided selective dry cow therapy

The objectives of this study were to (1) use partial budget analysis to estimate the cash impact for herds that switch from blanket dry cow therapy (BDCT) to culture- or algorithm-guided selective dry cow therapy (SDCT) and (2) conduct a sensitivity analysis to investigate effects in situations where SDCT increased clinical and subclinical mastitis risk during the subsequent lactation. A partial budget model was created using Monte Carlo simulation with @Risk software. Expenditures associated with dry-off procedures and health outcomes (clinical and subclinical mastitis) during the first 30 d in milk were used to model herd-level effects, expressed in units of US dollars per cow dry-off. Values for each economic component were derived from findings from a recent multisite clinical trial, peer-reviewed journal articles, USDA databases, and our experiences in facilitating the implementation of SDCT on farms. Fixed values were used for variables expected to have minimal variation within the US dairy herd population (e.g., cost of rapid culture plates) and sampling distributions were used for variables that were hypothesized to vary enough to effect the herd net cash impact of one or more DCT approach(es). For Objective 1, herd-level udder health was assumed to be unaffected by the implementation of SDCT. For culture-guided SDCT, producers could expect to save an average of +$2.14 (-$2.31 to $7.23 for 5th and 95th percentiles) per cow dry-off as compared with BDCT, with 75.5% of iterations being ≥$0.00. For algorithm-guided SDCT, the mean net cash impact was +$7.85 ($3.39-12.90) per cow dry-off, with 100% of iterations being ≥$0.00. The major contributors to variance in cash impact for both SDCT approaches were percent of quarters treated at dry-off and the cost of dry cow antibiotics. For Objective 2, we repeated the partial budget model with the 30-d clinical and subclinical mastitis incidence increasing by 1, 2, and 5% (i.e., risk difference = 0.01, 0.02, and 0.05) in both SDCT groups compared with BDCT. For algorithm-guided SDCT, average net cash impacts were ≥$0.00 per cow dry-off (i.e., cost effective) when mastitis incidence increased slightly. However, as clinical mastitis incidence increased, economic returns for SDCT diminished. These findings indicate that when SDCT is implemented appropriately (i.e., no to little negative effect on health), it might be a cost-effective practice for US herds under a range of economic conditions.

Osteoarthritis year in review 2020: epidemiology & therapy

This personal choice of research themes and highlights from within the past year (1 May 2019 to 14 April 2020) spans descriptive, analytical-observational, and intervention studies. Descriptive estimates of the burden of osteoarthritis continue to underscore its position as a leading cause of disability worldwide, but whose burden is often felt greatest among disadvantaged and marginalised communities. Many of the major drivers of that burden are known but epidemiological studies continue the important work of elaborating on their timing, dose, specificity, and reversibility and placing them within an appropriate multi-level framework. A similar process of elaboration is seen also in studies (re-)estimating the relative benefits and risks of existing interventions, in some cases helping to identify low-value care, unwarranted variation, and initiating processes of deprescribing and decommissioning. Such research need not engender therapeutic nihilism. Our review closes by highlighting some emerging evidence on the efficacy and safety of novel therapeutic interventions and with a selective roll-call of methodological and meta-research in OA illustrating the continued commitment to improving research quality.

Effect of reproductive management programs for first service on replacement dairy heifer economics

Our objective was to evaluate cash flow for dairy heifers managed for first service with programs that relied primarily on insemination at detected estrus (AIE), timed AI (TAI), or a combination of both. Holstein heifers from 2 commercial farms were randomized to receive first service with sexed semen after the beginning of the AI period (AIP) at 12 mo of age with 1 of 3 treatments: (1) PGF+AIE (n = 317): AIE after PGF_2α injections every 14 d (up to 3) starting at the beginning of the AIP; heifers not AIE 9 d after the third PGF_2α were enrolled in the 5d-Cosynch (5dCP) protocol; (2) ALL-TAI (n = 315): TAI after ovulation synchronization with the 5dCP protocol; and (3) PGF+TAI (n = 334): AIE after 2 PGF_2α injections 14 d apart (second PGF_2α at beginning of AIP). If not AIE 9 d after the second PGF_2α, the 5dCP protocol was used for TAI. After first service heifers were AIE or received TAI after the 5dCP with conventional semen. Individual heifer cash flow (CF) for up to a 15-mo period (d 0 = beginning of AIP) was calculated using reproductive cost (rearing only), feed cost (rearing only), income over feed cost (lactation only), calf value, operating cost, and with or without replacement cost. A stochastic analysis with Monte Carlo simulation was used to estimate differences in CF for a range of market values for inputs and outputs. Time to pregnancy for up to 100 d after the beginning of the AIP was analyzed by Cox's proportional regression, binary data with logistic regression, and continuous outcomes by ANOVA. Time to pregnancy (hazard ratio and 95% CI) was reduced for the ALL-TAI versus the PGF+AIE treatment (1.20; 1.02-1.42), but it was similar for ALL-TAI and PGF+TAI (1.13; 0.95-1.33) and the PGF+AIE and PGF+TAI treatments (1.07; 0.91-1.25). The proportion of heifers not pregnant by 100 d did not differ (PGF+AIE = 7.0%; PGF+TAI = 6.5%; ALL-TAI = 6.8%). When including replacement cost, CF ($/slot per 15 mo) differences were $51 and $42 in favor of the PGF+TAI and ALL-TAI compared with the PGF+AIE treatment, and $9 in favor of the PGF+TAI compared with the ALL-TAI treatment but did not differ statistically. Excluding heifers that were replaced to evaluate the effect of timing of pregnancy differences only, the difference in CF between the PGF+AIE with the PGF+TAI and ALL-TAI treatment was the same (i.e., $15) and favored the programs that used more TAI, but also did not differ statistically. Stochastic simulation results were in line with those of the deterministic analysis confirming the benefit of the programs that used more TAI. We concluded that submission of heifers for first service with TAI only or TAI in combination with AIE generated numerical differences in CF of potential value to commercial dairy farms. Reduced rearing cost and increased revenue during lactation increased CF under fixed (not statistically significant) or simulated variable market conditions.

Randomized controlled non-inferiority trial investigating the effect of 2 selective dry-cow therapy protocols on antibiotic use at dry-off and dry period intramammary infection dynamics

Selective dry-cow therapy (SDCT) could be used to reduce antibiotic use on commercial dairy farms in the United States but is not yet widely adopted, possibly due to concerns about the potential for negative effects on cow health. The objective of this study was to compare culture- and algorithm-guided SDCT programs with blanket dry-cow therapy (BDCT) in a multi-site, randomized, natural exposure, non-inferiority trial for the following quarter-level outcomes: antibiotic use at dry-off, dry period intramammary infection (IMI) cure risk, dry period new IMI risk, and IMI risk at 1 to 13 d in milk (DIM). Two days before planned dry-off, cows in each of 7 herds were randomly allocated to BDCT, culture-guided SDCT (cult-SDCT), or algorithm-guided SDCT (alg-SDCT). At dry-off, BDCT cows received an intramammary antibiotic (500 mg of ceftiofur hydrochloride) in all 4 quarters. Antibiotic treatments were selectively allocated to quarters of cult-SDCT cows by treating only quarters from which aseptically collected milk samples tested positive on the Minnesota Easy 4Cast plate (University of Minnesota, St. Paul, MN) after 30 to 40 h of incubation. For alg-SDCT cows, antibiotic treatments were selectively allocated at the cow level, with all quarters receiving antibiotic treatment if the cow had either a Dairy Herd Improvement Association test somatic cell count >200,000 cells/mL during the current lactation or 2 or more clinical mastitis cases during the current lactation. All quarters of all cows were treated with an internal teat sealant. Intramammary infection status at enrollment and at 1 to 13 DIM was determined using standard bacteriological methods. The effect of treatment group on dry period IMI cure, dry period new IMI, and IMI risk at 1 to 13 DIM was determined using generalized linear mixed models (logistic), with marginal standardization to derive risk difference (RD) estimates. Quarter-level antibiotic use at dry-off for each group was BDCT (100%), cult-SDCT (45%), and alg-SDCT (45%). The crude dry period IMI cure risk for all quarters was 87.5% (818/935), the crude dry period new IMI risk was 20.1% (764/3,794), and the prevalence of IMI at 1 to 13 DIM was 23% (961/4,173). Non-inferiority analysis indicated that culture- and algorithm-guided SDCT approaches performed at least as well as BDCT for dry period IMI cure risk. In addition, the final models indicated that the risks for each of the 3 IMI measures were similar between all 3 treatment groups (i.e., RD estimates and 95% confidence intervals all close to 0). These findings indicate that under the conditions of this trial, culture- and algorithm-guided SDCT can substantially reduce antibiotic use at dry-off without negatively affecting IMI dynamics.

Randomized controlled trial investigating the effect of 2 selective dry-cow therapy protocols on udder health and performance in the subsequent lactation

The objective of this study was to compare culture- and algorithm-guided selective dry-cow therapy (SDCT) programs with blanket dry-cow therapy (BDCT) in a multi-site, randomized, natural exposure clinical trial for the following cow-level outcomes: clinical mastitis, removal from the herd, and Dairy Herd Improvement Association (DHIA) test-day milk yield and SCC measures during the first 120 d in milk (DIM). Two days before planned dry-off, cows in each of 7 herds were randomly allocated to BDCT, culture-guided SDCT (cult-SDCT), or algorithm-guided SDCT (alg-SDCT). At dry-off, BDCT cows received an intramammary antibiotic (500 mg of ceftiofur hydrochloride) in all 4 quarters. Antibiotic treatments were selectively allocated to quarters of cult-SDCT cows by only treating quarters from which aseptically collected milk samples tested positive on a rapid culture system after 30 to 40 h of incubation. For alg-SDCT cows, antibiotic treatments were selectively allocated at the cow level, with all quarters receiving antibiotic treatment if the cow met at least one of the following criteria: (1) any DHIA test with a somatic cell count >200,000 cells/mL during the current lactation, and (2) ≥2 clinical mastitis cases during the current lactation. All quarters of all cows were treated with an internal teat sealant. Clinical mastitis and removal from the herd events (i.e., culling or death) and DHIA test-day data from dry-off to 120 DIM were extracted from herd records. Hazard ratios (HR) for the effect of treatment group on clinical mastitis and removal from the herd during 1 to 120 DIM were determined using Cox proportional hazards regression. The effects of treatment group on test-day log_e-transformed SCC and milk yield were determined using linear mixed models. Final models indicated that either SDCT program was unlikely to increase clinical mastitis risk (HR_{cult-SDCT/BDCT} = 0.82, 95% CI: 0.58, 1.15; HR_{alg-SDCT/BDCT} = 0.83, 95% CI: 0.63, 1.09) or test-day log_eSCC (cult-SDCT minus BDCT = 0.05, 95% CI: -0.09, 0.18; alg-SDCT minus BDCT = 0.07, 95% CI: -0.07, 0.21). Risk of removal from the herd and test-day milk yield were similar between treatment groups. Findings from this study indicate that culture- or algorithm-guided SDCT can be used at dry-off without negatively affecting cow health and performance in early lactation.

A reproductive management program aimed at increasing reinsemination of nonpregnant dairy cows at detected estrus resulted in similar reproductive performance to a program that favored timed artificial insemination

The objective of this experiment was to compare time to pregnancy and proportion of cows not pregnant 210 d after first service for cows managed for second and subsequent artificial insemination (AI) services with a reproductive management program that promoted reinsemination at detected estrus (AIE) or a program that promoted timed AI (TAI). After first service, lactating Holstein cows were blocked by parity and randomly assigned to d 32 Resynch (D32R; n = 464) or AIE Resynch (AIER; n = 512). To determine the effect of management strategies on time to pregnancy and cows not pregnant by the end of a 210 d at-risk period after first AI service, cows remained in AIER and D32R until pregnancy or herd exit. Cows in D32R received a GnRH treatment 32 ± 3 d after AI (first treatment intervention; FTI). Nonpregnancy diagnosis was conducted 7 d later by transrectal ultrasonography when nonpregnant cows with a corpus luteum (CL) ≥15 mm completed the Resynch protocol (PGF_2α, 56 h later GnRH, and 16 to 18 h later TAI) and cows without a CL (NoCL cows) were enrolled in a PreG-Ovsynch protocol (GnRH, 7 d later GnRH, 7 d later PGF_2α, 56 h later GnRH, and 16 to 18 h TAI) to receive TAI. For the AIER treatment, nonpregnant cows with a CL ≥15 mm observed by transrectal ultrasonography 32 ± 3 d after AI (i.e., FTI) received PGF_2α to induce estrus. Cows not AIE within 7 d were enrolled in Resynch (GnRH, 7 d later PGF_2α, 56 h later GnRH, and 16 to 18 h TAI). Cows in the NoCL group in AIER were enrolled in PreG-Ovsynch. Detection of estrus was performed based on visual observation of behavioral signs of estrus and tail-paint removal. Binomial data were analyzed with logistic regression and time to event data with Cox's proportional regression. After the FTI, a greater proportion of cows were AIE in AIER than D32R (36.0 vs. 11.9%) and more cows were AIE within 7 d of the FTI for AIER (25.0%) than D32R (4.8%). Overall pregnancy per AI at 68 ± 3 d after AI did not differ (AIER = 35.5% vs. D32R = 34.7%). The hazard of pregnancy up to 210 d after first AI for all cows enrolled (hazard ratio = 1.04, 95% CI 0.90 to 1.19) and for cows that received treatments only (D32R = 308, AIER = 349; hazard ratio = 1.00, 95% CI 0.85 to 1.19) did not differ. We conclude that a program aimed at increasing the proportion of cows reinseminated at detected estrus by treatment with PGF_2α at 32 ± 3 d after AI may be an alternative strategy for dairy farms that prefer or need to inseminate more cows at detected estrus rather than by TAI.

Midfoot osteoarthritis: potential phenotypes and their associations with demographic, symptomatic and clinical characteristics

OBJECTIVE

To investigate the demographic, symptomatic, clinical and structural foot characteristics associated with potential phenotypes of midfoot osteoarthritis (OA).

DESIGN

Cross-sectional study of 533 community-dwelling adults aged ≥50 years with foot pain in the past year. Health questionnaires and clinical assessments of symptoms, foot structure and function were undertaken. Potential midfoot OA phenotypes were defined by the pattern of radiographic joint involvement affecting either the medial midfoot (talonavicular, navicular-1^st cuneiform, or cuneiform-1^st metatarsal joint), central midfoot (2^nd cuneiform-metatarsal joint), or both medial and central midfoot joints. Multivariable regression models with generalised estimating equations were used to investigate the associations between patterns of midfoot joint involvement and symptomatic, clinical and structural characteristics compared to those with no or minimal midfoot OA.

RESULTS

Of 879 eligible feet, 168 had medial midfoot OA, 103 central midfoot OA, 76 both medial and central midfoot OA and 532 no/minimal OA. Having both medial and central midfoot OA was associated with higher pain scores, dorsally-located midfoot pain (OR 2.54, 95%CI 1.45, 4.45), hallux valgus (OR 1.76, 95%CI 1.02, 3.05), flatter foot posture (β 0.44, 95%CI 0.12, 0.77), lower medial arch height (β 0.02, 95%CI 0.01, 0.03) and less subtalar inversion and 1^st MTPJ dorsiflexion. Isolated medial midfoot OA and central midfoot OA had few distinguishing clinical characteristics.

CONCLUSIONS

Distinct phenotypes of midfoot OA appear challenging to identify, with substantial overlap in symptoms and clinical characteristics. Phenotypic differences in symptoms, foot posture and function were apparent in this study only when both the medial and central midfoot were involved.

Reproductive performance of replacement dairy heifers submitted to first service with programs that favor insemination at detected estrus, timed artificial insemination, or a combination of both

Our objective was to compare the insemination dynamics and time to pregnancy for up to 100 d after the beginning of the artificial insemination period (AIP) for heifers managed with first artificial insemination (AI) service programs that relied primarily on insemination at detected estrus (AIE) after PGF_2α treatments, timed artificial insemination (TAI), or a combination of both. Holstein heifers were randomly assigned to receive first AI service with sex-selected semen after 368 ± 10 d of age with (1) AIE after synchronization of estrus with up to 3 PGF_2α treatments every 14 d starting on the first day of the AIP (PGF+AIE; n = 317). Heifers not AIE up to 9 d after the third PGF_2α received a 5-d Cosynch protocol with progesterone supplementation [GnRH + controlled internal drug release insert (CIDR)-5 d-CIDR removal and PGF_2α-3 d-GnRH and TAI] before TAI. Heifers detected in estrus from CIDR removal and PGF_2α until the day before TAI received AIE with no GnRH treatment; (2) 2 PGF_2α treatments 14 d apart with the second treatment at the beginning of the AIP (PGF+TAI; n = 334). Heifers received AIE for up to 9 d after the second PGF_2α treatment. Heifers not AIE received TAI after the 5-d Cosynch protocol and (3) TAI after the 5-d Cosynch protocol (ALL-TAI; n = 315). Heifers failing to conceive to a previous AI received a subsequent AI with conventional semen at detected estrus or TAI after the 5-d Cosynch protocol. Binomial outcomes were analyzed by logistic regression, whereas time to AI and pregnancy were analyzed with Cox's regression. The hazard of first AI up to 45 d of the AIP was greater for ALL-TAI than for PGF+AIE [hazard ratio (HR) = 1.72; 95% confidence interval (CI) =1.45 to 2.03] and PGF+TAI (HR = 1.51; 95% CI = 1.28 to 1.77), but similar for PGF+AIE and PGF+TAI (HR = 1.14; 95% CI = 0.97 to 1.33). A greater proportion of heifers received AIE in PGF+AIE (98.7%) than in PGF+TAI (78.5%). Overall, first service pregnancy per AI did not differ (PGF+AIE = 42.0%; PGF+TAI = 47.3%, ALL-TAI = 43.8%). Time to pregnancy was reduced for ALL-TAI compared with PGF+AIE (HR = 1.20, 95% CI = 1.02 to 1.42), but was similar to that of PGF+TAI (HR = 1.13, 95% CI = 0.96 to 1.33). Time to pregnancy did not differ for PGF+AIE and PGF+TAI (HR = 1.07, 95% CI = 0.91 to 1.25). Median days to pregnancy were 27, 23, and 21 for heifers in PGF+AIE, PGF+TAI, and ALL-TAI, respectively. We concluded that an ALL-TAI program for first service reduced time to pregnancy, albeit a relatively small reduction, when compared with a program that relied primarily on AIE after induction of estrus with PGF_2α treatments. The program that combined synchronization of estrus and TAI (PGF+TAI) resulted in similar time to pregnancy than the predominant TAI and predominant AIE programs.

Differential effects of a single dose of oral calcium based on postpartum plasma calcium concentration in Holstein cows

Our objectives were to determine (1) the effect of a single dose of an oral Ca bolus within 24 h after parturition on plasma Ca concentration, (2) the response of primiparous (PP) and multiparous (MP) cows to this supplementation strategy, and (3) differential responses based on plasma Ca at enrollment. For objective 1, cows from 1 commercial dairy in New York State were enrolled within 19 h after parturition (mean ± standard deviation = 8.3 ± 5.3 h) and randomized within parity group (first, second, and ≥third) to control [CON (n = 25); no placebo] or a single dose bolus treatment [BOL (n = 25); 3 oral Ca boluses supplying 54 to 64 g of Ca]. Plasma Ca was measured repeatedly between 1 and 24 h following treatment. For objectives 2 and 3, cows on 6 commercial farms in New York State were assigned to treatment as for objective 1 (CON, n = 1,973; BOL, n = 1,976). Herd records for health, reproduction, and Dairy Herd Improvement Association test day milk production were collected. Mixed effect multivariable models were developed using repeated measures ANOVA, Poisson regression, or proportional hazard models. Objective 2 analyses considered treatment with periparturient risk factors, whereas objective 3 analyses also considered Ca status. No difference was observed for plasma Ca between 1 and 24 h after treatment. Primiparous cows assigned to BOL calving at >712 d old had decreased risk of one or more health disorders [≤30 d in milk; risk ratio (RR) = 0.65, 95% confidence interval (CI) = 0.51 to 0.84] and those with body condition score >3.5 responded to BOL with increased milk production (CON = 31.7 ± 1.1, BOL = 35.1 ± 1.1 kg/d), as did those with days carried calf >277 (CON = 31.9 ± 1.0, BOL = 34.7 ± 1.0 kg/d). Reduced risk of one or more health disorders was observed in parity ≥3 (RR = 0.85, 95% CI = 0.81 to 0.89) and MP cows with body condition score >3.5 (retained placenta; RR = 0.70, 95% CI = 0.58 to 0.84) or that were lame (displaced abomasum; RR = 0.49, 95% CI = 0.32 to 0.75). Differential responses for PP cows by Ca status were minimal. For MP cows with low plasma Ca, BOL decreased risk of additional Ca treatment (≤1.8 mmol/L; RR = 0.57, 95% CI = 0.40 to 0.80) as well as risk of one or more health disorders (≤2.15 mmol/L; RR = 0.90, 95% CI = 0.85 to 0.95). Supplementation with a single oral dose of Ca could be targeted to periparturient risk groups for improved health. Calcium status did not differentiate responses of PP cows, but MP cows with low Ca at parturition had improved health status when supplemented.

Randomized noninferiority trial comparing 2 commercial intramammary antibiotics for the treatment of nonsevere clinical mastitis in dairy cows

The purpose was to evaluate 2 intramammary treatments for mild-to-moderate cases of clinical mastitis in a noninferiority comparison. Noninferiority trials are intended to show whether a given treatment, hetacillin potassium, has at least comparable efficacy as the reference treatment, ceftiofur hydrochloride. Treatments can be deemed inferior to the reference treatment by an amount less than the margin of noninferiority, or inconclusive if the confidence interval crosses the margin of noninferiority. Cows with clinical mastitis from 6 farms were considered for enrollment. Using a randomized design, cows with mild or moderate mastitis in 1 quarter were assigned to on-label treatment with either ceftiofur or hetacillin. A total of 596 cows met the criteria needed for continued enrollment. Treatment distribution resulted in 309 cows in the ceftiofur group and 287 cows in the hetacillin group. Mixed regression analysis was performed for the following outcomes: bacteriological cure, pathogen cure, clinical cure, postevent milk production and linear score, and survival to d 30 and 60. Cox proportional hazards analysis was used to describe treatment effect on survival and mastitis risks. Bacteriological cure, defined as absence of causative organism in samples retrieved at d 14 and 21 postmastitis, was similar between groups. No significant statistical differences were found in cure risk, and noninferiority of hetacillin relative to ceftiofur for bacteriological cure was conclusive (hetacillin=67%, ceftiofur=72%). Absence of a pathogen on both follow-up samples designated a cow as a pathogen cure. Pathogen cure was similar between treatment groups and noninferiority of hetacillin relative to ceftiofur was shown (hetacillin=35%, ceftiofur=32%). Clinical cure (hetacillin=68%, ceftiofur=64%), postevent milk production (hetacillin=37.0kg, ceftiofur=38.2kg), and linear scores (hetacillin=3.4, ceftiofur=3.1) were also not statistically different between treatment groups. Noninferiority of hetacillin relative to ceftiofur was shown for survival to d 30 and survival to d 60, whereas hetacillin was more likely to have a clinical cure than ceftiofur by d 4. No differences were seen between groups when Cox proportional hazards were performed, neither for exit from the herd in the 60 d following the event nor in the risk for a subsequent mastitis event. These findings can be used to develop farm-specific protocols for clinical mastitis treatment.

Clinical diagnosis of symptomatic midfoot osteoarthritis: cross-sectional findings from the Clinical Assessment Study of the Foot

OBJECTIVE

To derive a multivariable diagnostic model for symptomatic midfoot osteoarthritis (OA).

METHODS

Information on potential risk factors and clinical manifestations of symptomatic midfoot OA was collected using a health survey and standardised clinical examination of a population-based sample of 274 adults aged ≥50 years with midfoot pain. Following univariable analysis, random intercept multi-level logistic regression modelling that accounted for clustered data was used to identify the presence of midfoot OA independently scored on plain radiographs (dorso-plantar and lateral views), and defined as a score of ≥2 for osteophytes or joint space narrowing in at least one of four joints (first and second cuneometatarsal, navicular-first cuneiform and talonavicular joints). Model performance was summarised using the calibration slope and area under the curve (AUC). Internal validation and sensitivity analyses explored model over-fitting and certain assumptions.

RESULTS

Compared to persons with midfoot pain only, symptomatic midfoot OA was associated with measures of static foot posture and range-of-motion at subtalar and ankle joints. Arch Index was the only retained clinical variable in a model containing age, gender and body mass index. The final model was poorly calibrated (calibration slope, 0.64, 95% CI: 0.39, 0.89) and discrimination was fair-to-poor (AUC, 0.64, 95% CI: 0.58, 0.70). Final model sensitivity and specificity were 29.9% (95% CI: 22.7, 38.0) and 87.5% (95% CI: 82.9, 91.3), respectively. Bootstrapping revealed the model to be over-optimistic and performance was not improved using continuous predictors.

CONCLUSIONS

Brief clinical assessments provided only marginal information for identifying the presence of radiographic midfoot OA among community-dwelling persons with midfoot pain.

Effect of extending the interval from Presynch to initiation of Ovsynch in a Presynch-Ovsynch protocol on fertility of timed artificial insemination services in lactating dairy cows

The specific objective of this study was to determine if increasing the interval between the Presynch and Ovsynch portion of the Presynch-Ovsynch protocol (Presynch: PGF2α-14 d-PGF2α and Ovsynch: GnRH-7 d-PGF2α-56 h-GnRH-16-20 h-timed artificial insemination) from 12 to 14 d would reduce the fertility of lactating dairy cows not detected in estrus after Presynch that receive timed artificial insemination (TAI). Cows from 4 commercial dairy farms (n=3,165) were blocked by parity (primiparous vs. multiparous) and randomly assigned to a 12 (PSOv14-12; n=1,566) or 14 d (PSOv14-14; n=1,599) interval between the second PGF2α (PGF) injection of Presynch (P2) and the beginning of Ovsynch. Cows detected in estrus any time between P2 and the day of the TAI were inseminated (AIED group). From a subgroup of cows (177 and 150 in PSOv14-12 and PSOv14-14, respectively), ovarian parameters and ovulation were evaluated through determination of concentrations of progesterone (P4) in blood and transrectal ultrasonography at the time of the first GnRH (GnRH1) and the PGF injection of Ovsynch. Overall, 52.8% (n=1,671) of the cows were AIED, whereas 47.2% (n=1,494) received TAI. For cows that received TAI, pregnancies per artificial insemination 39 d after artificial insemination were similar for PSOv14-12 (36.3%) and PSOv14-14 (36.0%) but were greater for primiparous (41.5%) than multiparous cows (33.6%). Pregnancy loss from 39 to 105 d after artificial insemination was similar for PSOv14-12 (4.8%) and PSOv14-14 (8.6%), for primiparous (6.4%) and multiparous cows (7.0%), but a tendency for a treatment by parity interaction was observed. Both treatments had a similar proportion of cows with a follicle ≥ 10 mm and similar follicle size at GnRH1; however, the ovulatory response to GnRH was greater for PSOv14-12 (62.2%) than PSOv14-14 (46.4%). A greater proportion of cows with a functional corpus luteum (75.3 vs. 65.6%) and greater concentrations of P4 (3.9 vs. 3.3 ng/mL) at GnRH1 in PSOv14-14 than PSOv14-12 may have compensated for the reduction in fertility expected due to reduced ovulatory response to GnRH1. We concluded that extending the interval from Presynch to Ovsynch from 12 to 14 reduced ovulatory response to GnRH1 but did not reduce the fertility of cows that received TAI when cows were inseminated in estrus after presynchronization. Thus, farms that combine AIED and TAI during the Presynch-Ovsynch protocol may use a 14-d interval between Presynch and Ovsynch to simplify their management without reducing fertility of cows receiving TAI.

Is long-term physical activity safe for older adults with knee pain?: a systematic review

OBJECTIVE

To determine whether long-term physical activity is safe for older adults with knee pain.

DESIGN

A comprehensive systematic review and narrative synthesis of existing literature was conducted using multiple electronic databases from inception until May 2013. Two reviewers independently screened, checked data extraction and carried out quality assessment. Inclusion criteria for study designs were randomised controlled trials (RCTs), prospective cohort studies or case control studies, which included adults of mean age over 45 years old with knee pain or osteoarthritis (OA), undertaking physical activity over at least 3 months and which measured a safety related outcome (adverse events, pain, physical functioning, structural OA imaging progression or progression to total knee replacement (TKR)).

RESULTS

Of the 8614 unique references identified, 49 studies were included in the review, comprising 48 RCTs and one case control study. RCTs varied in quality and included an array of low impact therapeutic exercise interventions of varying cardiovascular intensity. There was no evidence of serious adverse events, increases in pain, decreases in physical function, progression of structural OA on imaging or increased TKR at group level. The case control study concluded that increasing levels of regular physical activity was associated with lower risk of progression to TKR.

CONCLUSIONS

Long-term therapeutic exercise lasting 3 to 30 months is safe for most older adults with knee pain. This evidence supports current clinical guideline recommendations. However, most studies investigated selected, consenting older adults carrying out low impact therapeutic exercise which may affect result generalizability.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2014:CRD42014006913.

Vasectomy: a long-term study of its effects on testicular endocrine function in man

Plasma testosterone, luteinizing hormone (L.H.) and follicle stimulating (F.S.H.) were measured before operation in 39 males, aged 26 to 53 years with 2 to 5 children, seeking vasectomy for contraceptive purposes. These measurements were repeated at 3 and 12 months after vasectomy. Levels of L.H. at 12 months were significantly higher than pre-vasectomy levels, suggesting some degree of decreased Leydig cell function. However, testosterone and F.S.H. levels were similar at the three sampling times. Continuing yearly measurements for at least 5 years are planned.

Neuroplasticity in the mesolimbic dopamine system and cocaine addiction

The main characteristics of cocaine addiction are compulsive drug use despite adverse consequences and high rates of relapse during periods of abstinence. A current popular hypothesis is that compulsive cocaine use and cocaine relapse is due to drug-induced neuroadaptations in reward-related learning and memory processes, which cause hypersensitivity to cocaine-associated cues, impulsive decision making and abnormal habit-like learned behaviours that are insensitive to adverse consequences. Here, we review results from studies on the effect of cocaine exposure on selected signalling cascades, growth factors and physiological processes previously implicated in neuroplasticity underlying normal learning and memory. These include the extracellular signal-regulated kinase (ERK) signalling pathway, brain-derived neurotrophic factor (BDNF), glutamate transmission, and synaptic plasticity (primarily in the form of long-term potentiation and depression, LTP and LTD). We also discuss the degree to which these cocaine-induced neuroplasticity changes in the mesolimbic dopamine system mediate cocaine psychomotor sensitization and cocaine-seeking behaviours, as assessed in animal models of drug addiction. Finally, we speculate on how these factors may interact to initiate and sustain cocaine psychomotor sensitization and cocaine seeking.

Functional genomic and serological analysis of the protective immune response resulting from vaccination of macaques with an NS1-truncated influenza virus

We are still inadequately prepared for an influenza pandemic due to the lack of a vaccine effective for subtypes to which the majority of the human population has no prior immunity and which could be produced rapidly in sufficient quantities. There is therefore an urgent need to investigate novel vaccination approaches. Using a combination of genomic and traditional tools, this study compares the protective efficacy in macaques of an intrarespiratory live influenza virus vaccine produced by truncating NS1 in the human influenza A/Texas/36/91 (H1N1) virus with that of a conventional vaccine based on formalin-killed whole virus. After homologous challenge, animals in the live-vaccine group had greatly reduced viral replication and pathology in lungs and reduced upper respiratory inflammation. They also had lesser induction of innate immune pathways in lungs and of interferon-sensitive genes in bronchial epithelium. This postchallenge response contrasted with that shortly after vaccination, when more expression of interferon-sensitive genes was observed in bronchial cells from the live-vaccine group. This suggested induction of a strong innate immune response shortly after vaccination with the NS1-truncated virus, followed by greater maturity of the postchallenge immune response, as demonstrated with robust influenza virus-specific CD4+ T-cell proliferation, immunoglobulin G production, and transcriptional induction of T- and B-cell pathways in lung tissue. In conclusion, a single respiratory tract inoculation with an NS1-truncated influenza virus was effective in protecting nonhuman primates from homologous challenge. This protection was achieved in the absence of significant or long-lasting adverse effects and through induction of a robust adaptive immune response.

Integrated molecular signature of disease: analysis of influenza virus-infected macaques through functional genomics and proteomics

Recent outbreaks of avian influenza in humans have stressed the need for an improved nonhuman primate model of influenza pathogenesis. In order to further develop a macaque model, we expanded our previous in vivo genomics experiments with influenza virus-infected macaques by focusing on the innate immune response at day 2 postinoculation and on gene expression in affected lung tissue with viral genetic material present. Finally, we sought to identify signature genes for early infection in whole blood. For these purposes, we infected six pigtailed macaques (Macaca nemestrina) with reconstructed influenza A/Texas/36/91 virus and three control animals with a sham inoculate. We sacrificed one control and two experimental animals at days 2, 4, and 7 postinfection. Lung tissue was harvested for pathology, gene expression profiling, and proteomics. Blood was collected for genomics every other day from each animal until the experimental endpoint. Gross and microscopic pathology, immunohistochemistry, viral gene expression by arrays, and/or quantitative real-time reverse transcription-PCR confirmed successful yet mild infections in all experimental animals. Genomic experiments were performed using macaque-specific oligonucleotide arrays, and high-throughput proteomics revealed the host response to infection at the mRNA and protein levels. Our data showed dramatic differences in gene expression within regions in influenza virus-induced lesions based on the presence or absence of viral mRNA. We also identified genes tightly coregulated in peripheral white blood cells and in lung tissue at day 2 postinoculation. This latter finding opens the possibility of using gene expression arrays on whole blood to detect infection after exposure but prior to onset of symptoms or shedding.

Liver transplantation for primary or metastatic sarcoma to the liver

Sarcoma is generally a rare disease in the US, with poor survival in patients with both primary angiosarcoma and metastatic disease from sarcoma and GIST. In order to determine if liver transplantation for sarcoma is a realistic option, we examined records of all patients in the US component of the Israel Penn International Transplant Tumor Registry were reviewed. Those patients with liver failure from primary or metastatic liver sarcoma were evaluated. Patient outcome analysis was then performed. Patient and tumor demographics were reviewed as well as patient survival after transplantation. 19 patients are identified having received liver transplantation after treatment for sarcoma of the liver, 6 patients with primary hepatic sarcoma and 13 patients with metastatic sarcoma of the liver. Recurrence was almost universal in 18 of 19 patients (95%) after a median interval of 6 months. Survival for the group as a whole was 47% for 1-year, 15% for 3-years and 5% for 5-years. Given the early recurrence of tumor and meager 1-year survival outcome, liver transplantation is a poor therapeutic choice for patients with either primary or metastatic liver sarcoma, including high-grade leiomyosarcoma (GIST) regardless of primary site or primary therapy.

Laparoscopic right living donor nephrectomy

INTRODUCTION

Left laparoscopic donor nephrectomy (LDN) is preferred over right LDN due to technical ease. The purpose of this study was to compare results between right and left LDN and thereby determine whether substantial experience with right LDN can provide results equivalent to left LDN.

METHODS

All LDN from 2000 to 2004 were reviewed, and right LDN data compared to left LDN data. Statistical analyses included chi-square and Student t tests.

RESULTS

Two hundred thirteen left LDN (84%) were compared to 40 right LDN (16%). Donor age, gender, race, and body mass index, and multiple arteries were similar in right and left LDN groups. Operative and cold ischemia times were similar, but warm ischemia was longer for right LDN (3:55 +/- 1:22 minutes) than left LDN (3.18 +/- 1:06 minutes; P = .004). Despite this, renal allograft function was similar on postoperative day 7 (creatinine 1.77 +/- 1.21 for right LDN, 1.7 +/- 1.5 for left LDN) and at 1 year (right LDN 1.5 +/- 0.4, left LDN 1.23 +/- 0.28). Graft survival rate in the right LDN at 1 year was 97.5%.

CONCLUSIONS

This large experience with right LDN indicates that results comparable to left LDN can be obtained. This observation increases the options for LDN in patients with multiple left renal arteries, or with right renal cysts, or with right kidneys that are smaller in size compared to the contralateral left kidney.

A prospective, pilot study of early corticosteroid cessation in high-immunologic-risk patients: the Cincinnati experience

BACKGROUND

The first prospective trial of steroid withdrawal dedicated to high-immunologic-risk patients is reported herein.

METHODS

Twenty-five patients were enrolled prospectively in an IRB-approved HIPAA-compliant protocol. Immunosuppression included corticosteroid withdrawal (CSWD) at 7 days, tacrolimus (target trough level 4 to 8 ng/mL), sirolimus (target trough level 8 to 12 ng/mL), and Mycophenolate Mofetil (2 g/d). Induction with daclizumab (2 mg/kg) on posttransplant days (PTD) 0 and 14 was administered to the first 10 patients. The protocol for the next 15 patients was modified because of high acute rejection rates to include received T-cell-depleting antibody induction therapy with thymoglobulin (1.5 mg/kg) on PTDs 0 and 2 followed by daclizumab on Postoperative day (POD) 14. Recipient inclusion criteria included: (1) repeat transplant recipients; or (2) patients with a peak PRA > or =25%. All rejection episodes were diagnosed by biopsy and graded using Banff '97 criteria.

RESULTS

Twenty-five patients were enrolled and median follow-up was 402 days. Forty percent of recipients were black, 68% of patients were repeat transplant recipients, 68% received deceased donor kidneys, and 36% had a peak flow PRA >25%. Overall acute rejection, graft survival, and patient survival rates of 40%, 88%, and 96%, respectively, were observed for the duration of the study. Acute rejection occurred in 6 of 10 patients (60%) with daclizumab induction; however, acute rejection rates fell to 27% when thymoglobulin was introduced (P = .1).

CONCLUSIONS

This study supports our previous observations in a multivariate analysis of early CSWD patients, wherein polyclonal antibody induction therapy reduced acute rejection. High-immunologic-risk patients may be able to undergo early CSWD with acceptable rates of acute rejection.

Laparoscopic Living Donor Nephrectomy for Kidneys With Multiple Arteries

INTRODUCTION

Laparoscopic donor nephrectomy (LDN) involving kidneys with multiple arterial vessels is limited to a small number of reports, with all but two series reporting fewer than 25 patients. Moreover, outside of the pioneering centers at the University of Maryland and Johns Hopkins, no series of at least 25 patients has been published confirming these experience. The present study presents the largest series of LDN of donor kidneys with multiple arterial vessels outside of these two pioneering programs.

METHODS

All LDN performed at the University of Cincinnati from 2000 to 2004 were reviewed. Results between LDN kidneys with a single vessel and those with multiple vessels were compared. Statistical analysis included chi-square and Student t test.

RESULTS

Of 240 LDN, 37 were performed for kidneys with multiple vessels (15%): nine right kidneys (25%) and 28 left kidneys (75%). Cold ischemia time was longer for the multiple vessel organs (46 +/- 24 minutes) than for single vessel organs (35 +/- 13 minutes; P = .001), and warm ischemia time was longer for the multiple vessel kidneys (4:20 +/- 2:05 minutes) than single vessel kidneys (3:13 +/- 0:47 minutes; P = .001). Recipient renal function (serum creatinine) was similar for multiple and single artery donors at postoperative day 7 (1.76 +/- 1.38 and 1.7 +/- 1.47) and at postoperative day 365 (1.06 +/- 0.3 and 1.34 +/- 0.44).

CONCLUSIONS

This experience confirms results from other series in documenting the safety and reproducibility of LDN for kidneys with multiple arterial vessels.

PI 3-kinase inhibition: a therapeutic target for respiratory disease

Asthma and COPD (chronic obstructive pulmonary disease) are a growing major health burden, which, despite improvements in disease management, still require new effective treatments. As our understanding of the cellular and molecular processes which govern respiratory diseases improves, the range of potential therapeutic targets increase. PI 3-kinases (phosphoinositide 3-kinases) are a family of closely related enzymes, which play pivotal roles in a diverse array of cellular mechanisms. In the present paper, we review the evidence for PI 3-kinase involvement in various cellular processes underlying asthma and COPD generated through inhibitor studies and gene-targeting approaches, and discuss the prospects for PI 3-kinase inhibition as a future therapeutic strategy for the treatment of respiratory disease.

Loss of glutamine synthetase in the human epileptogenic hippocampus: possible mechanism for raised extracellular glutamate in mesial temporal lobe epilepsy

BACKGROUND

High extracellular glutamate concentrations have been identified as a likely trigger of epileptic seizures in mesial temporal lobe epilepsy (MTLE), but the underlying mechanism remains unclear. We investigated whether a deficiency in glutamine synthetase, a key enzyme in catabolism of extracellular glutamate in the brain, could explain the perturbed glutamate homoeostasis in MTLE.

METHODS

The anteromedial temporal lobe is the focus of the seizures in MTLE, and surgical resection of this structure, including the hippocampus, leads to resolution of seizures in many cases. By means of immunohistochemistry, western blotting, and functional enzyme assays, we assessed the distribution, quantity, and activity of glutamine synthetase in the MTLE hippocampus.

FINDINGS

In western blots, the expression of glutamine synthetase in the hippocampus was 40% lower in MTLE than in non-MTLE samples (median 44 [IQR 30-58] vs 69 [56-87]% of maximum concentration in standard curve; p=0.043; n=8 and n=6, respectively). The enzyme activity was lower by 38% in MTLE vs non-MTLE (mean 0.0060 [SD 0.0031] vs 0.0097 [0.0042] U/mg protein; p=0.045; n=6 and n=9, respectively). Loss of glutamine synthetase was particularly pronounced in areas of the MTLE hippocampus with astroglial proliferation, even though astrocytes normally have high content of the enzyme. Quantitative immunoblotting showed no significant change in the amount of EAAT2, the predominant glial glutamate transporter in the hippocampus.

INTERPRETATION

A deficiency in glutamine synthetase in astrocytes is a possible molecular basis for extracellular glutamate accumulation and seizure generation in MTLE. Further studies are needed to define the cause, but the loss of glutamine synthetase may provide a new focus for therapeutic interventions in MTLE.

Molecular species composition of rat liver phospholipids by ESI-MS/MS: the effect of chromatography

Using electrospray ionization tandem mass spectrometry (ESI-MS/MS) this study shows that the loss of glycerophospholipid (GPL) after chromatography was unevenly distributed across the GPL molecular species. Both TLC and HPLC caused a preferential loss of GPL with 0 to 3 double bonds: 20% and 7.2% for choline glycerophosphates (PC) and 19.7% and 7.5% for ethanolamine glycerophosphates (PE), respectively. A consequence of these losses was that GPLs containing fatty acids with four or more double bonds had a greater contribution to the total after chromatography. ESI-MS/MS analysis also showed that PC molecular species with four or more double bonds migrated at the front of the TLC band of PCs. GPLs extracted from TLC plates occasionally contained PCs that were smaller than those in the original extract. These low molecular mass PCs were easily reduced to alcohols and formed derivatives with 2,4-dinitrophenylhydrazine, suggesting that aldehydes were generated by the oxidation of unsaturated fatty acids. Directly analyzing lipid extracts by ESI-MS/MS without preliminary chromatographic separation gives an accurate distribution of GPL molecular species in lipid mixtures. However, the ionization of the phospholipids in the electrospray jet maximized at relatively low concentrations of GPL. There was a linear response between phospholipid mass and ion intensity for concentrations around 1-2 nmol/ml for both PC and PE. The total ion intensity continued to increase with concentrations above 1-2 nmol/ml, but the response was non-linear.

Long-term depression in the nucleus accumbens: a neural correlate of behavioral sensitization to cocaine

A compelling model of experience-dependent plasticity is the long-lasting sensitization to the locomotor stimulatory effects of drugs of abuse. Adaptations in the nucleus accumbens (NAc), a component of the mesolimbic dopamine system, are thought to contribute to this behavioral change. Here we examine excitatory synaptic transmission in NAc slices prepared from animals displaying sensitization 10-14 days after repeated in vivo cocaine exposure. The ratio of AMPA (alpha-amino-3-hydroxy-5-methyl-4- isoxazole propionic acid) receptor- to NMDA (N-methyl-d-aspartate) receptor-mediated excitatory postsynaptic currents (EPSCs) was decreased at synapses made by prefrontal cortical afferents onto medium spiny neurons in the shell of the NAc. The amplitude of miniature EPSCs at these synapses also was decreased, as was the magnitude of long-term depression. These data suggest that chronic in vivo administration of cocaine elicits a long-lasting depression of excitatory synaptic transmission in the NAc, a change that may contribute to behavioral sensitization and addiction.

Preparation and incorporation of probe-labeled apoA-I for fluorescence resonance energy transfer studies of rHDL

Apolipoprotein A-I (apoA-I), the major constituent of HDL, plays an essential role in regulating cholesterol metabolism, acting as the physiological activator of lecithin: cholesterol acyltransferase, which converts cholesterol to cholesterol ester. Thiol-reactive fluorescent probes attached to cysteine-containing apoA-I mutants are currently being used to investigate the "LCAT active" conformation of lipid-bound apoA-I. Herein, we report new methodologies allowing rapid expression, fluorescent labeling, and recombinant HDL (rHDL) preparation for use in apoA-I in fluorescence resonance energy transfer (FRET) studies. Cysteine-containing mutant forms of human apoA-I were cloned into the pTYB12 vector containing a T7 promoter, a modified self-splicing protein element (intein), and a small affinity tag [chitin binding domain (CBD)]. The fusion proteins were expressed in Escherichia coli, isolated from cell lysates, and bound to a chitin-affinity column. Release of mature human apoA-I was initiated by the addition of DTT, which induced self-cleavage at the COOH terminus of the intein - CBD fusion protein. ApoA-I was further purified by Q-sepharose and then used for fluorescent probe labeling. Discoidal rHDL were then prepared with donor and/or acceptor labeled apoA-I and characterized with respect to their size, composition and ability to activate LCAT.

Upregulation of the cardiac monocarboxylate transporter MCT1 in a rat model of congestive heart failure

BACKGROUND

Cardiac metabolism becomes more dependent on carbohydrates in congestive heart failure (CHF), and lactate may be used as an important respiratory substrate. Monocarboxylate transporter 1 (MCT1) promotes cotransport of lactate and protons into and out of heart cells and conceivably flux of lactate between cells, because it is abundantly present in the intercalated disk.

METHODS AND RESULTS

Six weeks after induction of myocardial infarction (MI) in Wistar rats, left ventricular end-diastolic pressures were >15 mm Hg, signifying CHF. MCT1 and connexin43 protein levels in CHF were 260% and 20%, respectively, of those in sham-operated animals (Sham), and the corresponding mRNA signals were 181% and not significantly changed, respectively. Confocal laserscan immunohistochemistry and quantitative immunogold cytochemistry showed that MCT1 density was much higher in CHF than in Sham both at the surface membrane and in the intercalated disk. In CHF, a novel intracellular pool of MCT1 appeared to be associated with cisternae, some close to the T tubules. In contrast, connexin43 particles, seen exclusively at gap junctions, were substantially fewer. Maximum lactate uptake was 107+/-15 mmol. L(-1). min(-1) in CHF and 42+/-6 mmol. L(-1). min(-1) in Sham cells (P<0.05). The K(m) values were between 7 and 9 mmol/L (P=NS).

CONCLUSIONS

In cardiomyocytes from CHF rats, (1) the amount of functional MCT1 in the sarcolemma, including in the intercalated disk, is increased several-fold; (2) a new intracellular pool of MCT1 appears; (3) another disk protein, connexin43, is much reduced; and (4) increased reliance on lactate and other monocarboxylates (eg, pyruvate) could provide tight metabolic control of high-energy phosphates.

Early Th1/Th2 cell polarization in the absence of IL-4 and IL-12: T cell receptor signaling regulates the response to cytokines in CD4 and CD8 T cells

Differentiation of developing T cells into the type 1 (IFN-gamma-producing) or type 2 (IL-4-producing) subsets is a central theme of immune regulation. The balance of IL-4 and IL-12 present during T cell activation has been considered the major influence on type 1 versus type 2 development. Here we show that CD4 T cells can become biased towards type 1 or type 2 phenotypes during their initial activation in the absence of IL-4 or IL-12. This type of regulation is dependent on the balance of MAPkinase, protein kinase C, and calcineurin signaling after TCR engagement. Later maturation of Th1 or Th2 effectors is dependent on IL-12 or IL-4. However Tc1 CD8 effector development is independent of IL-12, and Tc2 cell generation requires both appropriate TCR signals and IL-4 early in effector development. Using an altered peptide ligand to stimulate TCR transgenic T cells, we show that altered signaling regulates the numbers of CD8 cells capable of developing into Tc2 effectors, and also their responsiveness to IL-4. Together, the results support a two-stage model of differentiation in which intermediate cells biased towards the type 1 or type 2 pathways after activation, are subsequently matured in response to IL-12 or IL-4, respectively.

Retrograde amnesia after hippocampal damage: recent vs. remote memories in two tasks

We review evidence from experiments conducted in our laboratory on retrograde amnesia in rats with damage to the hippocampal formation. In a new experiment reported here, we show that N-methyl-D-aspartate (NMDA)-induced hippocampal damage produced retrograde amnesia for both hidden platform and two-choice visible platform discriminations in the Morris water task. For both problems there was a significant trend for longer training-surgery intervals to be associated with worse retention performance. Little support is offered by our work for the concept that there is a process involving hippocampal-dependent consolidation of memories in extrahippocampal permanent storage sites. Long-term memory consolidation may take place within the hippocampus. The hippocampus may be involved permanently in storage and/or retrieval of a variety of relational and nonrelational memories if it was intact at the time of learning, even involving information which is definitely not affected in anterograde amnesia after hippocampal damage.

Validation of the Hasford score in a demographic study in chronic granulocytic leukaemia

Chronic granulocytic leukaemia (CGL) is a rare disease. For most patients the only curative treatment (an allogeneic stem cell transplant) is not available. Survival varies between a few months to many years from diagnosis, and an accurate prediction of the duration of survival could help patients and clinicians make informed decisions about the many treatment options. In 1984, the Sokal score was introduced to stratify patients into risk groups. Recently, a new prognostic scoring system was proposed by Hasford and co-workers for interferon treated patients. We have analysed survival on an unselected population based cohort of patients using both the Hasford and the Sokal scores. In the group overall, neither score was predictive of survival, but in younger patients (< 60 years) treated with interferon, the Hasford score was highly predictive of survival, dividing patients into groups with a five year survival of 77% (45 patients) v 33% (six patients) v 14% (31 patients) (p = 0.01).

Isoprostane levels in lipids extracted from atherosclerotic arteries of nonhuman primates

Nonhuman primates used in these studies had been fed for 5 years diets enriched with cholesterol and one of three classes of fatty acids: saturated, monounsaturated, or polyunsaturated fatty acids. Atherosclerotic iliac artery lipid extracts were quantitatively analyzed for cholesterol, cholesteryl esters, fatty acid composition, and a marker of lipid oxidation, the F(2)-isoprostanes. There was no significant difference in the mean accumulation of F(2)-isoprostanes among the different diet groups. To account for the small, individual variation in the arachidonate concentration the F(2)-isoprostane mass from each sample was normalized by dividing by arachidonate mass: F(2)-isoprostane mass/(mass arachidonate). At lower levels of cholesterol accumulation, the F(2)-isoprostane mass/(mass arachidonate) ratio was greater in lipids from POLY arteries compared to SAT arteries, but the reverse was true at high levels of cholesterol. F(2)-isoprostane/(mass arachidonate) increased with mole fraction linoleate for the SAT group, but decreased for the POLY group. In summary, these studies demonstrated that there is no simple explanation of how F(2)-isoprostane accumulation did not depend on the concentration of oxidizable lipids that promote free-radical lipid oxidation.