Floor-to-Stand Performance Among People Following Stroke.

OBJECTIVES: Studies have examined floor-to-stand performance in varied adult populations both quantitatively and qualitatively. Despite an elevated risk of falls and inability to independently return to stand after a fall, few have examined the ability to stand from the floor in patients recovering from stroke. There were 2 objectives of the study: to identify the relationships between floor-to-stand performance using a timed supine-to-stand test (TSS) and physical performance measures of gait, balance, and balance confidence among persons in the subacute phase after stroke; and to analyze descriptive strategies used in the completion of the TSS. METHODS: A cross-sectional design was implemented. Fifty-eight adults (mean age = 59.2 [standard deviation (SD) = 13.9] years; 34 [58.6%] men) who were in the subacute phase after ischemic or hemorrhagic stroke and who could stand from the floor with no more than supervision completed the TSS and physical performance assessments. RESULTS: The median time to complete the TSS in our sample was 13.0 (interquartile range = 15.5) seconds. TSS time was significantly correlated with physical performance tests, including the Timed "Up & Go" Test (ρ = 0.70), gait speed (ρ = -0.67), Dynamic Gait Index (ρ = -0.52), and Activities-Specific Balance Confidence Scale (ρ = -0.43). Thirty-two percent of the variance in TSS time was attributed to Timed "Up & Go" Test time and the use of the quadruped position to transition to standing. Participants who used a gait device were more likely to use a chair during rise to stand. CONCLUSION: The TSS demonstrates concurrent validity with physical performance measures. IMPACT: Findings serve to improve functional mobility examination after stroke and to formulate effective treatment interventions to improve floor-to-stand performance.

Nutritional considerations for a new era: A CF foundation position paper.

OBJECTIVE: To provide interim advice and considerations to the CF Community around CF nutrition in the current era. METHODS: The Cystic Fibrosis (CF) Foundation organized a multidisciplinary committee to develop a Nutrition Position Paper based on the rapidly changing nutrition landscape in CF, due in part to widespread use of cystic fibrosis transmembrane regulator highly effective modulator therapy (HEMT). Four workgroups were formed: Weight Management, Eating Behavior/Food Insecurity, Salt Homeostasis and Pancreatic Enzyme use. Each workgroup conducted their own focused review of the literature. RESULTS: The committee summarized current understanding of issues pertaining to the four workgroup topics and provided 6 key take-aways around CF Nutrition in the new era. CONCLUSION: People with CF (pwCF) are living longer, particularly with the advent of HEMT. The traditional high fat, high calorie CF diet may have negative nutritional and cardiovascular consequences as pwCF age. Individuals with CF may have poor diet quality, food insecurity, distorted body image, and an higher incidence of eating disorders. An increase in overweight and obesity may lead to new considerations for nutritional management, given potential effects of overnutrition on pulmonary and cardiometabolic parameters.

Towards precision home visiting: results at six months postpartum from a randomized pilot implementation trial to assess the feasibility of a precision approach to Family Spirit.

BACKGROUND: Shared implementation challenges at scale in early childhood home visiting have led researchers to explore precision home visiting as a promising service delivery mechanism to better address families' unique needs and build greater program efficiencies. This randomized controlled pilot study aimed to assess the acceptability of a precision approach to one home visiting model, Family Spirit® and explore potential differences between Precision Family Spirit (PFS) and Standard Family Spirit (Standard FS) on participant-home visitor relationship and maternal outcomes. METHODS: Participants (N = 60) were at least 14 years old, pregnant or within 2 months postpartum, and enrolled in Family Spirit. Four sites in Michigan were randomized 1:1 to deliver PFS (up to 17 core lessons plus up to 13 additional lessons as needed) or Standard FS (home visiting services as usual). Primary (program acceptability, participant satisfaction, home visitor-participant relationship quality, retention, adherence) and secondary (knowledge, quality of life, difficulty with parenting problems, substance use, depression, stress) outcomes at 6 months postpartum are presented. PFS participants also self-reported on quality of life, difficulty with parenting problems, stress, substance use, and concerns with sexual and reproductive health and self and child's nutrition status at each home visit. This informed which lessons they should receive. RESULTS: Mothers in both groups reported positive program acceptability, satisfaction, and home visitor-participant relationships at 6 months postpartum. However, open-ended feedback from Standard FS participants indicates that some lesson content may not be applicable to all participants. At 6 months, retention was 82.3% for PFS and 66.7% for Standard FS, and adherence was 30.1% for PFS and 20.6% for Standard FS. CONCLUSIONS: Preliminary findings indicate that precision home visiting may be acceptable and feasible. A definitive trial is needed to build on this pilot data, assess outcomes for mothers and children participating in a precision approach to home visiting as compared to standard home visiting, and ready this approach for scale. TRIAL REGISTRATION: ClinicalTrials.gov NCT03975530 (first posted on 05/06/2019).

Home visitor perspectives on implementing a precision approach to home visiting in communities serving Native American families.

Family Spirit (FS) is a federally endorsed evidence-based home visiting programs serving as a key prevention strategy for expectant families and families with young children. Like other home-visiting programs, it shares client challenges in retention and engagement during implementation. We assessed (1) the feasibility and acceptability of implementing a precision approach to FS; and (2) differences in approaches to FS delivery. Home visitors, serving primarily Native American families, that delivered a standard (N = 6) or a precision approach (N = 6) to FS across four study sites each participated in up to four virtual focus group discussions (FGDs) (N = 16). Facilitators and barriers to implementation were identified across the curriculum approach, relational and contextual levels. Facilitators: Relevant and culturally sensitive lessons, lesson structure, client-home visitor relationship, client buy-in, home visitor autonomy, leadership support, flexible funding, and training. Barriers: Irrelevant lessons, substance use content, missing topics, families experiencing crises, client and home visitor availability, client feedback, nonsupportive leadership, inadequate funding, and organizational policies and practices. The precision approach offers (1) tailoring of lessons that supports relevance of content to clients; and (2) a target timeframe that supports flexibility in lesson delivery. This model structure may improve client participation and retention.

Espíritu de Familia (FS) es un programa de visitas a casa con base en la evidencia y respaldado federalmente, el cual sirve como una estrategia clave de prevención para familias con niños pequeños que esperan otro niño. Tal como otros programas de visitas a casa, éste comparte los retos de los participantes en cuanto a retención y participación activa durante la implementación. Evaluamos 1) la factibilidad y accesibilidad de implementar un acercamiento de precisión a FS; y 2) las diferencias en cuanto al acercamiento del ofrecimiento de FS. Los visitadores a casa, quienes primariamente les sirven a familia nativo-americanas, y que ofrecieron un acercamiento estándar (N = 6) o uno de precisión (N = 6) a FS a través de 4 lugares de estudio, cada uno participó en un máximo de 4 discusiones virtuales de grupos de enfoque (N = 16). Los aspectos que facilitaron y las barreras a la implementación se identificaron a lo largo de los niveles de acercamiento, relacionales y contextuales del currículo. Aspectos que facilitaron: lecciones relevantes y culturalmente sensibles, estructura de lecciones, la relación entre el participante-casa y el visitador, la aceptación por parte del participante, la autonomía del visitador a casa, el apoyo de liderazgo, la flexibilidad de los fondos, así como el entrenamiento. Barreras: lecciones irrelevantes, contenido sobre uso de sustancias, temas que no se incluyeron, las familias que experimentaban una crisis, la disponibilidad del participante y del visitador, información aportada por el participante, falta de apoyo del liderazgo, fondos inadecuados, así como las políticas y prácticas organizacionales. El acercamiento de precisión ofrece 1) moldear las lecciones que apoyan la relevancia del contenido a los participantes; y 2) un definido marco de tiempo que apoya la flexibilidad del ofrecimiento de las lecciones. Esta estructura de modelo pudiera mejorar la participación y retención de participantes.

Le programme Family Spirit (FS, soit Esprit de Famille) est une programme américain, basé sur des données probantes, avalisé par le gouvernement américain, de visite à domicile, servant de stratégie de prévention clé pour les familles attendant un enfant ou les familles avec de jeunes enfants. Comme d'autres programmes de visite à domicile, ce programme partage des difficultés dans la rétention et l'engagement des clients durant la mise en oeuvre. Nous avons évalué 1) la fiabilité et l'acceptabilité de la mise en œuvre d'une approche de précision du FS; et 2) des différences dans les approches de l'application du FS. Les visiteurs à domicile, servant principalement des familles amérindiennes américaines, qui ont présenté une approche standard (N = 6) ou une approche de précision (N = 6) du FS et au travers de 4 sites d'étude chacun ont participé à jusqu'à 4 discussions de groupe d'étude virtuels (n = 16). Les aspects facilitateurs et les barrières à la mise en place ont été identifiés au travers de l'approche du curriculum, des niveaux relationnels et contextuels. Aspects de facilitation: leçons pertinentes et culturellement sensibles, structure de la leçon, relation client-visiteur à domicile, adhésion du client, autonomie du visiteur à domicile, soutient des dirigeants, budget flexible, formation. Barrières: leçons n'étant pas pertinentes, contenu d'usage de substance, sujets qui manquent, familles faisant l'expérience de crises, disponibilité du client et du visiteur à domicile, retour du client, dirigeants qui n'offrent aucun soutien, budget inadéquat, et politiques et pratiques organisationnelles. L'approche de précision offre 1) une adaptation sur mesure des leçons qui soutient la pertinence du contenu pour les clients; et 2) un délai ciblé qui soutient la flexibilité de l'enseignement. Cette structure de modèle peut améliorer la participation et la rétention.

Precision Family Spirit: a pilot randomized implementation trial of a precision home visiting approach with families in Michigan-trial rationale and study protocol.

BACKGROUND: Home visiting is a well-supported strategy for addressing maternal and child health disparities. However, evidence-based models generally share implementation challenges at scale, including engagement and retention of families. Precision home visiting may address this issue. This paper describes the first known pilot randomized implementation trial of a precision home visiting approach vs. standard implementation. Primary aims are to: 1) explore the acceptability and feasibility of a precision approach to home visiting and 2) examine the difference between Standard Family Spirit and Precision Family Spirit on participants' program satisfaction, client-home visitor relationship, goal alliance, and the impact of these factors on participant engagement and retention. Secondary aims are to explore potential differences on maternal behavioral and mental health outcomes and child development outcomes to inform sample size estimations for a fully powered study. METHODS: This is a pilot Hybrid Type 3 implementation trial. Four Michigan communities primarily serving the Native American families and already using Family Spirit were randomized by site to receive Standard Family Spirit or Precision Family Spirit. Participants include N = 60 mothers at least 14 years of age (pregnant or with a newborn < 2 months of age) currently enrolled in Family Spirit. Precision Family Spirit participants receive core lessons plus additional lessons based on needs identified at baseline and that emerge during the trial. Control mothers receive the standard sequence of Family Spirit lessons. Data is collected at baseline (< 2 months postpartum), and 2, 6, and 12 months postpartum. All Precision Family Spirit participants are invited to complete qualitative interviews at study midpoint and endpoint. All home visitors are invited to participate in focus groups between study midpoint and endpoint. Exploratory data analysis will assess feasibility, acceptability, client-home visitor relationship, retention, adherence, and potential differences in intervention outcomes. DISCUSSION: This trial will provide new information about the acceptability and feasibility of precision home visiting and pilot data on program satisfaction, client-home visitor relationship, goal alliance, retention, and targeted maternal-child intervention outcomes. Findings will inform the design of a fully powered randomized implementation trial of precision vs. standard home visiting. TRIAL REGISTRATION: ClinicalTrials.gov # NCT03975530 ; Registered on June 5, 2019.

Educating Providers in Return-to-Play Suggested Guidelines Postconcussion.

As the awareness of concussions increases, it is imperative to be able to evaluate, diagnose, and treat concussed individuals properly to prevent further complications or death. The primary purpose of this study was to compare a provider's current awareness and comfort level as it relates to the return-to-play guidelines for concussions. A secondary aim was to evaluate current protocols that are in use and determine whether they coincide with the suggested guidelines. An educational intervention was implemented to assess the knowledge and confidence of health care providers. The study design was a quantitative, convenient sample, pretest/posttest questionnaire. The questionnaire was administered to participants who were nurse practitioners prior to an educational PowerPoint presentation. At 8 weeks, the posttest was administered. Approximately 19% of individuals were not aware of a graded return-to-play protocols. The findings suggest that the educational intervention increased their confidence levels in making a diagnosis of a concussion, in assessing danger signs, and in understanding when to refer to a specialist. Additional supporting evidence from this study indicates that the educational intervention allowed the participants to achieve a greater comfort level in finding appropriate resources for them and their patients.

Enteral tube feeding for individuals with cystic fibrosis: Cystic Fibrosis Foundation evidence-informed guidelines.

Nutrition is integral to the care of individuals with cystic fibrosis (CF). Better nutritional status is associated with improved pulmonary function. In some individuals with CF, enteral tube feeding can be useful in achieving optimal nutritional status. Current nutrition guidelines do not include detailed recommendations for enteral tube feeding. The Cystic Fibrosis Foundation convened an expert panel to develop enteral tube feeding recommendations based on a systematic review of the evidence and expert opinion. These guidelines address when to consider enteral tube feeding, assessment of confounding causes of poor nutrition in CF, preparation of the patient for placement of the enteral feeding tube, management of the tube after placement and education about enteral feeding. These recommendations are intended to guide the CF care team, individuals with CF, and their families through the enteral tube feeding process.

Web-Based Intervention for Nutritional Management in Cystic Fibrosis: Development, Usability, and Pilot Trial.

OBJECTIVES: Usability and pilot testing of a web intervention (BeInCharge.org [BIC]) of behavior plus nutrition intervention for children with cystic fibrosis (CF) ages 4-9 years. METHODS: Think Aloud methodology was used with five mothers to assess usability and refine the intervention. A pilot trial was then conducted with 10 mothers of children with CF ages 4-9 years randomized to the web-based BIC or a Standard Care Control (STC). Change in weight gain for each group was compared in a pre-to-post design. RESULTS: Mothers rated the usability and clarity of BIC highly. The pilot trial showed children of mothers who received BIC had a significant change in weight pre-to-post-treatment (0.67 kg, p = .04). Change for the STC was not significant (0.41 kg, p = .10). CONCLUSIONS: A web-based behavior plus nutrition intervention appears promising in increasing weight gain in children with CF.

Nutritional outcomes following gastrostomy in children with cystic fibrosis.

OBJECTIVE: In 2005 the Cystic Fibrosis (CF) Foundation recommended that children with CF maintain a body mass index (BMI) ≥ 50th percentile. Our study evaluated if gastrostomy (GT) placement increases the likelihood of reaching that goal compared to a standardized nutrition protocol. STUDY DESIGN: Retrospective study of 20 children with CF ages 2-20 years with GTs placed from 2005 to 2010. Each case was pair-matched on age, sex, pancreatic status, BMI, and lung function with a nonGT child with CF. Outcome measures included nutritional status and lung function at 6 months and 1 year. RESULTS: At baseline, mean ± SD BMI Z-scores were similar (cases -1.19 ± 0.60, controls -1.10 ± 0.50; P = 0.10). Cases had a significant 6-month increase in mean BMI Z-score to -0.29 ± 0.84 compared to -1.02 ± 0.67 for controls (P < 0.001). By 1 year, the change in mean BMI Z-score was less different (cases -0.41 ± 0.76, controls -0.71 ± 0.51; P = 0.07). Both groups had stable lung function. From exact logistic regression analysis, the odds ratio for cases compared to controls of reaching BMI ≥ 50th percentile was 9.70 (95% CI: 1.05-484.7; P = 0.04) at 6 months and 3.65 (95%CI: 0.69-25.86; P = 0.16) at 1 year. CONCLUSION: Our study suggests that children with CF who receive GTs are more likely to achieve BMI ≥ 50th percentile than matched children without GTs.

Transient effectiveness of vitamin D2 therapy in pediatric cystic fibrosis patients.

BACKGROUND: The effectiveness of current treatment recommendations for vitamin D insufficiency in children with CF is unknown. Therefore, we assessed the effectiveness of vitamin D(2) 50,000 IU once daily for 28 days for vitamin D insufficiency. METHODS: Retrospective chart review of pediatric CF patients from 2006-2008. Vitamin D(2) 50,000 IU daily for 28 days was given to patients with 25-OHD <30 ng/mL and repeat 25-OHD levels were obtained after completion of therapy. RESULTS: One hundred forty-seven levels from 97 individuals were assessed. Success of treatment was 54% (n=80/147). Seventeen of 39 patients (43%) followed for an additional 6-18 months were able to maintain levels of >or=30 ng/mL. CONCLUSIONS: Vitamin D(2) 50,000 IU daily for 28 days was effective in correcting vitamin D insufficiency in approximately 50% of subjects. However, almost half of successfully treated patients were unable to maintain normal 25-OHD levels >6 months after completion of therapy, implying that this effect is transient.

Description of a standardized nutrition classification plan and its relation to nutritional outcomes in children with cystic fibrosis.

OBJECTIVE: Better nutrition enhances lung function and increases survival for children with cystic fibrosis (CF). Therefore, we developed a standardized strategy to evaluate nutritional status and create individualized treatment plans to ensure that all patients received the same high-quality care in a busy CF Center. METHODS: A quality improvement approach was undertaken to develop a novel nutrition classification strategy to identify and treat children with subtle manifestations of nutritional deficits in addition to those with obvious nutritional issues. RESULTS: During the 15-month study period, the median body mass index (BMI) percentile increased from 35.2 (0-95.9) to 42.0 (0-97.7), p < .005. Additionally, the number of children with a BMI >or=50th percentile increased by 11.8%. CONCLUSIONS: Adoption of a standardized approach to nutritional assessment and treatment led to significant improvement in nutritional outcomes of CF patients, demonstrating that systematic changes in clinical practice can improve clinical outcomes substantially over a short period of time.

Current treatment recommendations for correcting vitamin D deficiency in pediatric patients with cystic fibrosis are inadequate.

OBJECTIVES: To determine the prevalence of vitamin D deficiency (25-hydroxy vitamin D [25-OHD] levels in plasma <30 ng/mL) in pediatric patients with cystic fibrosis (CF), elucidate contributing factors for vitamin D deficiency, and determine the efficacy of ergocalciferol repletion strategies. STUDY DESIGN: Retrospective chart review of 262 pediatric patients from January 2003 to December 2006 with linear and logistic regression analyses. RESULTS: Vitamin D deficiency prevalence declined in the years studied from 86.5% to 46.2%. Patients >12 years old were more likely to have deficiency than patients <5 years old (odds ratio [OR], 3.44; 95% CI, 1.73-6.84). Levels obtained in spring and summer were less likely to be deficient compared with those obatained in fall (OR, 0.24; 95% CI, 0.10-0.61; and OR, 0.25; 95% CI, 0.11-0.61; respectively). Success of treatment with 50,000 IU of ergocalciferol once, twice, or 3 times weekly was 33%, 26%, and 43%, respectively. Ergocalciferol, when compared with no treatment, did not significantly increase the proportion of patients with follow-up levels > or =30 ng/mL (chi(2)P value = .80, .34, and .22, respectively). CONCLUSIONS: The prevalence of vitamin D deficiency is high, but declined with time. Age, forced expiratory volume in 1 second, and season were associated with 25-OHD levels. Despite 33% of patients responding to 50 000 IU of ergocalciferol once a week, this recommendation does not adequately treat most patients with CF who have vitamin D deficiency.

Cytoprotective agent in Lactobacillus bulgaricus extracts.

Adenosine 5'-diphosphoribose (ADP-ribose) has been identified as a significant contributor to the anti-cytotoxic activity of Lactobacillus bulgaricus extracts. Although the biological activities associated with the administration of probiotic bacteria and components thereof are sometimes attributed to the peptidoglycans that comprise a substantial portion of the Gram-positive bacterial cell wall, we found that the beta-nicotine adenine dinucleotide (NAD) hydrolysis product ADP-ribose was a significant contributor to the observed anti-cytotoxicity in our L. bulgaricus extracts. The ADP-ribose was isolated, identified, and quantitated by high performance liquid chromatography (HPLC) and by nuclear magnetic resonance (NMR) spectroscopy. ADP-ribose levels as low as 5 mg/L exhibited a measurable inhibition of tumor necrosis factor alpha (TNF-alpha) mediated cytotoxicity in an in vitro cell assay, whereas the ADP-ribose content of the L. bulgaricus extracts often exceeded 5 mg/g dry weight.

Enzymes for transgenic biosynthesis of long-chain polyunsaturated fatty acids.

Polyunsaturated fatty acids (PUFAs) are important for the normal development and function of all organisms, and are essential in maintaining human health. Impaired PUFA metabolism is thought to be associated with pathogenesis of many chronic diseases. Dietary supplementation of PUFAs, such as gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, which bypass the defective or dysfunctional steps of the biosynthetic pathway has been found to significantly alleviate the symptoms of the disease. These findings have drawn a great deal of interest from general public and food manufacturers. As the demand of these beneficial PUFAs has drastically increased in recent years, there are also increasing efforts in finding the alternate sources of PUFAs that are more economical and sustainable. One option is to modify the oil-seed crops to produce PUFAs through genetic engineering technique. This review examines the isolation, identification and expression of genes encoding the enzymes required for the biosynthesis of the above mentioned PUFAs in plants.

Identification of two novel microalgal enzymes involved in the conversion of the omega3-fatty acid, eicosapentaenoic acid, into docosahexaenoic acid.

Marine microalgae such as Pavlova and Isochrysis produce abundant amounts of the omega3-PUFAs (polyunsaturated fatty acids), EPA (eicosapentaenoic acid, 20:5n-3) and DHA (docosahexaenoic acid, 22:6n-3). The pathway leading to the conversion of EPA into DHA in these lower eukaryotes is not well established although it is predicted to involve an elongation step, catalysed by an elongating enzyme complex, leading to the conversion of EPA into omega3-DPA (omega-3-docosapentaenoic acid, 22:5n-3); followed by a desaturation step, catalysed by a Delta4-desaturase, which results in the conversion of DPA into DHA. To date, the enzymes involved in the elongation of EPA have not been identified from any lower eukaryote. In the present study, we describe the identification of microalgal genes involved in the two-step conversion of EPA into DHA. By expressed sequence tag analysis, a gene (pavELO) encoding a novel elongase was identified from Pavlova, which catalysed the conversion of EPA into omega3-DPA in yeast. Unlike any previously identified elongase from higher or lower eukaryotes, this enzyme displayed unique substrate specificity for both n-6 and n-3 C20-PUFA substrates, with no activity towards any C18- or C22-PUFA substrates. In addition, a novel Delta4-desaturase gene (IgD4) was isolated from Isochrysis, which was capable of converting omega3-DPA into DHA, as well as adrenic acid (22:4n-6) into omega6-DPA. Yeast co-expression studies, with pavELO and IgD4, revealed that these genes were capable of functioning together to carry out the two-step conversion of EPA into DHA.

Calcium kinetics are altered in clinically stable girls with cystic fibrosis.

Reduced bone mass in individuals with cystic fibrosis (CF) may result from alterations in calcium metabolism. Bone calcium deposition and resorption rates, calcium balance, and markers of bone turnover were assessed using stable isotopes of calcium in 22 prepubertal and pubertal girls with CF. Bone calcium deposition was associated with the availability of dietary calcium, total serum osteocalcin, and leptin concentrations. Reduced bone mass in individuals with CF may result from inadequate bone calcium (Ca) deposition, and excessive resorption, although these parameters have not been directly assessed in children with CF. We used stable Ca isotopes to measure rates of bone Ca deposition (Vo+), resorption, and retention in 22 clinically stable girls with CF (aged 7-18 yr). Rates of bone Ca deposition were determined by mathematically modeling the disappearance of iv Ca stable isotope ((42)Ca) for 6 d post dosing. Indirect markers of bone turnover and hormones associated with pubertal development were also assessed. Rates of bone Ca deposition and retention were highest during early puberty (Tanner stages 2 and 3). Calcium deposition rates in prepubertal (Tanner 1) and postmenarchal girls (Tanner stages 4 and 5) did not support substantial bone Ca retention. Net absorption of dietary Ca and serum osteocalcin and leptin concentrations were positively associated with Vo+. Time post menarche and serum leptin concentrations explained 91% of the variability in Vo+ (P = 0.0007). Serum total osteocalcin was low (10.9 +/- 5.4 ng/ml), and a substantial percentage of osteocalcin was undercarboxylated (54.3 +/- 11.8%). We concluded that increased calcium absorption and serum leptin concentrations were significantly associated with rates of bone Ca deposition, demonstrating an impact of nutritional status on this process. Rates of bone Ca deposition were lower than typically reported in healthy children, as were indirect markers of bone formation. These alterations in bone turnover contribute to reduced bone mass in girls with CF.

Endogenous fecal losses of calcium compromise calcium balance in pancreatic-insufficient girls with cystic fibrosis.

OBJECTIVE: Bone mineral density is compromised in individuals with cystic fibrosis (CF); calcium is the major bone mineral. This study examined the impact of endogenous fecal calcium (V(endo)) losses on calcium balance in girls with CF. Study design V(endo) was measured in 12 girls with CF (aged 7-18 years): 7 younger, premenarcheal girls with compromised nutritional status; and 5 older, postmenarcheal girls with adequate nutritional status. V(endo) was measured as the amount of intravenously administered (42)Ca, a calcium stable isotope, in stool relative to urine over 6 days. V(endo) was compared between pre- and postmenarcheal girls by Student's t test. Actual calcium balance [absorbed calcium-(urinary calcium (V(u))+V(endo))] was compared with estimated balance (assuming V(endo)=1.6 mg/kg/day calcium) by paired t test. RESULTS: V(endo) was 99.3+/-42.3 mg/day. By body weight, V(endo) was highest among premenarcheal girls (3.37+/-1.09 mg/kg/day), resulting in excess losses (>1.6 mg/kg/day) of 55.0+/-45.7 mg/day. Over 1 year, this represents 20.1+/-16.7 g of unattained bone calcium or 6.7+/-4.2% of the bone calcium content of these girls. CONCLUSIONS: V(endo) is a significant source of calcium loss in individuals with CF and may limit calcium availability for bone mineral deposition.

Efficiency of calcium absorption is not compromised in clinically stable prepubertal and pubertal girls with cystic fibrosis.

BACKGROUND: Reduced bone mass is common in both children and adults with cystic fibrosis (CF) and may be a consequence of inadequate calcium absorption. The effect of CF on intestinal calcium absorption and retention has not been described in children. OBJECTIVE: Calcium absorption and urinary losses were characterized in clinically stable girls with CF consuming self-selected diets and following usual pancreatic enzyme regimens. DESIGN: The percentage of calcium absorption was assessed in 23 girls (aged 7-18 y) with CF by using oral ((44)Ca) and intravenous ((42)Ca) stable isotopes. Girls were grouped according to Tanner stage of breast development. True calcium absorption (V(a)) was determined as the product of percentage calcium absorption and average 4-d daily calcium intake. Calcium balance was estimated by subtracting urinary calcium and estimated endogenous fecal losses from the measure of V(a). Analysis of variance was used to compare outcomes among pubertal groups, and regression analysis was used to describe the relations of percentage and total calcium absorption to calcium intake and of urinary calcium to sodium excretion. RESULTS: Percentage calcium absorption was inversely related to calcium intake. Percentage absorption and V(a) were similar to values observed in healthy girls in other studies. Total calcium absorption and estimated calcium balance were significantly greater among girls in early puberty (Tanner stages 2-3) than in prepubertal or late-pubertal girls (P < 0.05). Urinary calcium was positively related to urinary sodium excretion (P = 0.02). CONCLUSION: The efficiency of calcium absorption was not compromised in clinically stable girls with CF.

Recent advances in the study of fatty acid desaturases from animals and lower eukaryotes.

The biosynthesis of polyunsaturated fatty acids (PUFAs) in different organisms can involve a variety of pathways, catalyzed by a complex series of desaturation and elongation steps. A range of different desaturases have been identified to date, capable of introducing double bonds at various locations on the fatty acyl chain. Some recently identified novel desaturases include a delta4 desaturase from marine fungi, and a bi-functional delta5/delta6 desaturase from zebrafish. Using molecular genetics approaches, these desaturase genes have been isolated, identified, and expressed in variety of heterologous hosts. Results from these studies will help increase our understanding of the biochemistry of desaturases and the regulation of PUFA biosynthesis. This is of significance because PUFAs play critical roles in multiple aspects of membrane physiology and signaling mechanisms which impact human health and development.