Carnitine deficiency in surgical neonates receiving total parenteral nutrition

Carnitine plays a key role in the oxidation of fatty acids. Most solutions for parenteral nutrition do not contain carnitine. Because endogenous carnitine synthesis is insufficient in newborns, they are prone to developing a carnitine deficiency when they are dependent on total parenteral nutrition (TPN). Stimulated by the clinical observation of manifest clinical symptoms of carnitine deficiency in one patient, a study of 13 consecutive neonates who received TPN for over 2 weeks was begun. Their plasma carnitine levels before and during carnitine supplementation were determined. All patients had a carnitine intake far below the recommended minimal need of 11 mumol/kg per day. Although only three of them clearly showed clinical symptoms described as carnitine deficiency, carnitine supplementation for all neonates receiving TPN for over 2 weeks is recommended.     

Preferential release of newly synthesized 3H-acetylcholine from rat cerebral cortex slices in vitro

1. Slices of rat cerebral cortex after treatment with the irreversible cholinesterase inhibitor soman, were incubated for 5 min in a Krebs-Henseleit solution containing 25 mM KCl and (3)H-choline. Subsequently incubation was continued in a medium containing non-radioactive choline and this medium was replaced at 5 min intervals. The amounts of labelled and total acetylcholine (ACh) released into the medium and extracted from the slices were determined at intervals.2. After the initial 5 min contact with (3)H-choline, 44% of the newly synthesized ACh contained a choline moiety originating from the choline in the medium. During the initial 5 min and the subsequent incubation part of the labelled ACh was released. While the rate of total ACh release remained constant, that of the release of labelled ACh was highest in the 5 min period following the initial incubation with (3)H-choline and then declined exponentially.3. The ratio of labelled ACh/total ACh in the ACh released during the initial 5 min incubation with (3)H-choline and during the subsequent 5 min was about three times as high as that in the ACh extracted from the slices at the end of these incubation periods.4. The ratio of labelled ACh/total ACh in superficial layers of the slices was not higher than that in the total slices.5. The rates of release of labelled and unlabelled ACh decreased when calcium was omitted from the incubation medium and were restored when the calcium was added. This suggests that both labelled and unlabelled ACh were released from nerve endings. The efflux of (3)H-choline was not calcium dependent.6. It is concluded that labelled ACh newly synthesized from externally applied (3)H-choline does not exchange immediately with all other ACh in the tissue and has a greater chance of being released than unlabelled ACh.     

Transient neutropenia increases macrophage accumulation and cell proliferation but does not improve repair following intratendinous rupture of Achilles tendon

Neutrophils are the first leukocytes to invade tendons after an acute injury. They could modulate both the inflammatory response and early repair processes through the release of reactive species, cytokines, growth factors, and proteinases. However, the exact role of these cells in damaged tendons remains unclear. We investigated their role by inducing a transient neutropenia in C57BL/6 male mice using an anti‐Ly6C/Ly6G antibody. Placebo mice received only serum. The right Achilles tendon was sectioned and sutured using the 8‐strand technique, which allowed immediate weight bearing. A significant increase in macrophage accumulation and cell proliferation was observed in tendons from neutropenic animals compared to the placebo group at days 3 and/or 7 postinjury. However, there was a reduction in cell proliferation in a group of mice depleted in macrophages, indicating that macrophages play a role in cell replication in injured tendons. Lastly, the tendons of neutropenic and placebo mice had similar collagen content and mechanical properties at days 7, 14, and/or 28 postinjury. Our findings demonstrate that neutropenia modulates macrophage accumulation and cell proliferation, but overall, a reduction in neutrophil number has no significant effect on tendon repair. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1084–1091, 2010     

Cost–utility and cost-effectiveness of physical exercise during adjuvant chemotherapy

Introduction

A home-based, low-intensity physical activity program (Onco-Move) and a supervised, moderate-to-high intensity, combined resistance and aerobic exercise program (OnTrack) have proven to be effective in maintaining physical fitness and reducing fatigue among breast cancer patients undergoing adjuvant chemotherapy. This study evaluated the cost–utility and cost-effectiveness of Onco-Move and OnTrack.

Methods

A total of 230 patients were randomized to Onco-Move, OnTrack, or usual care (UC). Health outcomes included quality-adjusted life years (QALYs), general and physical fatigue, and physical fitness measured at baseline, end of chemotherapy, and 6-month follow-up. Societal costs included professional and informal health care, work absenteeism, and unpaid productivity costs. Cost data were based on 3-monthly questionnaires, supplemented by medication data obtained from pharmacies.

Results

Onco-Move is not likely to be cost-effective due to the relatively high willingness-to-pay necessary to reach reasonable probabilities of cost-effectiveness (QALY, general and physical fatigue). Incremental cost-effectiveness ratios for OnTrack compared to UC were €26,916/QALY, €788/1-point decrease in general fatigue and €1402/1-point decrease in physical fatigue. The probability of OnTrack being cost-effective ranged from 31% at a willingness-to-pay (WTP) of €0–79% at a WTP of €80,000/QALY, 97% at a WTP of €15,000/1-point decrease in general fatigue, and 86% at a WTP of €24,000/1-point decrease in physical fatigue. Both interventions had a low probability of being cost-effective for physical fitness. The probability of cost-effectiveness for both interventions was greater among compliant participants.

Conclusions

Onco-Move is not likely to be cost-effective. Depending on the decision-makers’ willingness-to-pay, OnTrack could be considered cost-effective in comparison with UC. Trial registration Clinical trial registration number of the Netherlands Trial Register—NTR2159.

     

Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between dietary sources of vitamin B-12 (meat, fish and shellfish, eggs, dairy) and serum vitamin B-12, using cross-sectional data of 600 Dutch community-dwelling adults (≥65 years). Dietary intake was assessed with a validated food frequency questionnaire. Vitamin B-12 concentrations were measured in serum. Associations were studied over tertiles of vitamin B-12 intake using P for trend, by calculating prevalence ratios (PRs), and splines. Whereas men had significantly higher vitamin B-12 intakes than women (median (25th–75th percentile): 4.18 (3.29–5.38) versus 3.47 (2.64–4.40) μg/day), serum vitamin B-12 did not differ between the two sexes (mean ± standard deviation (SD): 275 ± 104 pmol/L versus 290 ± 113 pmol/L). Higher intakes of dairy, meat, and fish and shellfish were significantly associated with higher serum vitamin B-12 concentrations, where meat and dairy—predominantly milk were the most potent sources. Egg intake did not significantly contribute to higher serum vitamin B-12 concentrations. Thus, dairy and meat were the most important contributors to serum vitamin B-12, followed by fish and shellfish.     

Peer Reviewed: Risk and Protective Factors for Tobacco Use Among 8th- and 10th-Grade African American Students in Virginia

Introduction

Few studies have simultaneously examined the influence of multiple domains of risk and protective factors for smoking among African Americans. This study identified individual-peer, family, school, and community risk and protective factors that predict early cigarette use among African American adolescents.

Methods

Data from 1,056 African American 8th and 10th graders who completed the 2005 Community Youth Survey in Virginia were analyzed by using logistic regression.

Results

The prevalence of smoking among the weighted sample population was 11.2%. In univariate analyses, the strongest predictors of smoking were low academic achievement, peer drug use, and early substance use (individual domain). In multivariate analyses, these factors and being in the 10th grade were significant predictors. The single protective factor in multivariate analyses was in the school domain (rewards for prosocial behavior in the school setting). When family and community variables were entered into a model in which individual-peer and school factors were controlled for, these variables were not significantly associated with smoking, and they failed to improve model fit.

Conclusion

These findings suggest that tobacco prevention programs that aim to increase school connectedness while decreasing youth risk behaviors might be useful in preventing cigarette use among African American adolescents. Given the relative importance of peer drug use in predicting smoking among African American youth, more work is needed that explores the accuracy of youths'' perceptions of their friends'' cigarette use and how family factors may moderate this risk.     

Contraceptive needs of women seeking care from a publicly funded sexually transmitted infection clinic

Objectives

To determine the contraceptive needs [including emergency contraception (EC)] of women seeking care from a publicly funded sexually transmitted infection (STI) clinic and to better understand women's knowledge of and attitudes towards EC.

Methods

An anonymous survey was administered to 197 women seeking services at one Chicago Department of Public Health STI clinic.

Results

After excluding women unlikely to become pregnant within the next year because of age, sexual orientation, hysterectomy and those who desired pregnancy (n=47), data from 150 women were available for analysis. Thirteen percent were using “very effective” contraception (intrauterine contraception, implant or sterilization) and 26% were using “effective” contraception (contraceptive pill, patch, ring or injectable). Approximately 23% (95% CI 16.5–30.0%) may have benefited from immediate use of EC as they reported at least one act of unprotected intercourse within the past 5 days.

Conclusion

Many women seeking care from public STI clinics are at high risk of unintended pregnancy. A substantial number of women have an immediate need of EC at the time of their clinical visit. Efforts are needed to improve provision of EC as well as effective ongoing contraception for this population.     

Carvedilol induces greater control of β2- than β1-adrenoceptor-mediated inotropic and lusitropic effects by PDE3, while PDE4 has no effect in human failing myocardium

The β-blockers carvedilol and metoprolol provide important therapeutic strategies for heart failure treatment. Therapy with metoprolol facilitates the control by phosphodiesterase PDE3, but not PDE4, of inotropic effects of catecholamines in human failing ventricle. However, it is not known whether carvedilol has the same effect. We investigated whether the PDE3-selective inhibitor cilostamide (0.3 μM) or PDE4-selective inhibitor rolipram (1 μM) modified the positive inotropic and lusitropic effects of catecholamines in ventricular myocardium of heart failure patients treated with carvedilol. Right ventricular trabeculae from explanted hearts of nine carvedilol-treated patients with terminal heart failure were paced to contract at 1 Hz. The effects of (-)-noradrenaline, mediated through β₁-adrenoceptors (β₂-adrenoceptors blocked with ICI118551), and (-)-adrenaline, mediated through β₂-adrenoceptors (β₁-adrenoceptors blocked with CGP20712A), were assessed in the absence and presence of the PDE inhibitors. The inotropic potency, estimated from –logEC₅₀s, was unchanged for (-)-noradrenaline but decreased 16-fold for (-)-adrenaline in carvedilol-treated compared to non-β-blocker-treated patients, consistent with the previously reported β₂-adrenoceptor-selectivity of carvedilol. Cilostamide caused 2- to 3-fold and 10- to 35-fold potentiations of the inotropic and lusitropic effects of (-)-noradrenaline and (-)-adrenaline, respectively, in trabeculae from carvedilol-treated patients. Rolipram did not affect the inotropic and lusitropic potencies of (-)-noradrenaline or (-)-adrenaline. Treatment of heart failure patients with carvedilol induces PDE3 to selectively control the positive inotropic and lusitropic effects mediated through ventricular β₂-adrenoceptors compared to β₁-adrenoceptors. The β₂-adrenoceptor-selectivity of carvedilol may provide protection against β₂-adrenoceptor-mediated ventricular overstimulation in PDE3 inhibitor-treated patients. PDE4 does not control β₁- and β₂-adrenoceptor-mediated inotropic and lusitropic effects in carvedilol-treated patients.