Effects of platelet rich plasma and acellular bone marrow on gene expression patterns and DNA content of equine suspensory ligament explant cultures.

REASONS FOR PERFORMING STUDY: Suspensory ligament (SL) desmitis is a common source of lameness. The results of this study will determine if blood-derived products stimulate SL matrix synthesis and have potential as regenerative therapies for SL desmitis OBJECTIVES: To determine if various blood-based biological products including plasma, blood, PRP, platelet poor plasma (PPP) and ABM aspirate stimulates anabolic and/or catabolic pathways in suspensory ligaments (SL). METHODS: The body of the SL was harvested from 6 horses and used to establish explant cultures. Explants were cultured in plasma, blood, PRP, PPP or ABM at concentrations of 10, 50 or 100%. Anabolic responses were assessed by use of quantitative PCR for collagens type I and III, cartilage oligomeric matrix protein (COMP) and decorin. Total DNA and collagen protein content were also measured. Catabolic reactions were measured by quantitative PCR for matrix metalloproteinases 3 and 13 (MMP-3, MMP-13). RESULTS: Acellular bone marrow aspirate at 100% stimulated decorin and COMP mRNA synthesis more than all other treatments at all concentrations. No treatment at any concentration stimulated the catabolic gene MMP-13; only 50% ABM stimulated MMP-13 mRNA expression. CONCLUSIONS: Acellular bone marrow is indicated, and might be preferred to plasma, blood or PPP, as a blood-based biological source for SL tissue regenerative therapy. Long-term, placebo controlled case studies are indicated to determine if ABM aids in recovery from SL desmitis. POTENTIAL RELEVANCE: Bone marrow aspirate is an autogenous, readily available biological source for SL regenerative therapy where the aim is to stimulate matrix synthesis.

Pediatric obesity prevention and management.

Obesity has reached epidemic proportions worldwide in turn redirecting the goals of the Pediatric well care visit. There is no effective pharmacological or surgical treatment available for this entity but if left unaddressed it can lead to detrimental medical complications. Several known contributors to obesity exist which allow the development of successful prevention programs. Prior to initiating such a program, a pediatric practitioner should be equipped with the skills of identification of overweight and its risk factors as well as strong knowledge of treatment options. We attempt to provide the appropriate guidelines for childhood obesity prevention in this review.

Evaluation of an automated system for the collection of packed RBCs, platelets, and plasma.

BACKGROUND: This study evaluated the quality of WBC-reduced platelets, RBCs, and plasma collected on a new system (Trima, Gambro BCT) designed to automate the collection of all blood components. The study also evaluated donor safety and suitability of these components for transfusion. STUDY DESIGN AND METHODS: In Phase I, the quality of the components collected on the new system was evaluated by standard in vitro and in vivo testing methods. Results were compared to those from control components collected by currently approved standard methods. In Phase II, additional collections were performed to evaluate the acceptability of the new system and the safety of platelets collected. RESULTS: In vivo 24-hour RBC recovery was 76.8 +/- 3.1 percent for the test RBC units and 77.1 +/- 4.4 percent recovery for whole-blood (control) RBCs. The differences between test and control platelet results in the in vivo and in vitro assays were not clinically significant. Plasma clotting factors and fibrinogen levels met international standards. The system was well accepted by donors, and no major adverse donor reactions were reported for the 68 procedures performed. No problems were reported with transfusing the blood components collected. CONCLUSION: Blood components collected with the Trima are equivalent to currently available components, and they meet the applicable regulatory standards. This system provides consistent, standardized components with predictable yields. It provides the option of fully automating the collection of all blood components.

American Academy of Pediatrics. Committee on Nutrition. Calcium requirements of infants, children, and adolescents.

This statement is intended to provide pediatric caregivers with advice about the nutritional needs of calcium of infants, children, and adolescents. It will review the physiology of calcium metabolism and provide a review of the data about the relationship between calcium intake and bone growth and metabolism. In particular, it will focus on the large number of recent studies that have identified a relationship between childhood calcium intake and bone mineralization and the potential relationship of these data to fractures in adolescents and the development of osteoporosis in adulthood. The specific needs of children and adolescents with eating disorders are not considered.

Efficacy and safety of lovastatin in adolescent males with heterozygous familial hypercholesterolemia: a randomized controlled trial.

CONTEXT: Heterozygous familial hypercholesterolemia (HeFH) is a common disorder associated with early coronary artery disease, especially in men. The age at which drug therapy should be started is still controversial, as is the use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). OBJECTIVE: To assess the lipid-lowering efficacy, biochemical safety, and effect on growth and sexual development of lovastatin in adolescent boys with HeFH. DESIGN: One-year, double-blind, placebo-controlled, balanced, 2-period, 2-arm randomized trial. In the first period (24 weeks), lovastatin was increased at 8 and 16 weeks and the dosage remained stable during the second period (24 weeks). The study was conducted between 1990 and 1994. SETTING: Fourteen pediatric outpatient clinics in the United States and Finland. PATIENTS: Boys aged 10 to 17 years with HeFH. Of 132 randomized subjects (67 intervention, 65 placebo), 122 (63 intervention, 59 placebo) and 110 (61 intervention, 49 placebo) completed the first and second periods, respectively. INTERVENTION: Lovastatin, starting at 10 mg/d, with a forced titration at 8 and 16 weeks to 20 and 40 mg/d, respectively, or placebo. MAIN OUTCOME MEASURES: The primary efficacy outcome measure was low-density lipoprotein cholesterol (LDL-C). Primary safety measures were growth and sexual development. RESULTS: Compared with placebo, LDL-C levels of patients receiving lovastatin decreased significantly (P<.001) by 17%, 24%, and 27% receiving dosages of 10, 20, and 40 mg/d, respectively, and remained 25 % lower than baseline at 48 weeks. Growth and sexual maturation assessed by Tanner staging and testicular volume were not significantly different between the lovastatin and placebo groups at 24 weeks (P = .85) and 48 weeks (P = .33); neither were serum hormone levels or biochemical parameters of nutrition. However, the study was underpowered to detect significant differences in safety parameters. Serum vitamin E levels were reduced with lovastatin treatment consistent with reductions in LDL-C, the major carrier of vitamin E in the circulation. CONCLUSIONS: This study in adolescent boys with HeFH confirmed the LDL-C-reducing effectiveness of lovastatin. Comprehensive clinical and biochemical data on growth, hormonal, and nutritional status indicated no significant differences between lovastatin and placebo over 48 weeks, although further study is required.

Normal growth in high-risk hyperlipidemic children and adolescents with dietary intervention.

OBJECTIVE: The aim of this study was to assess the safety and efficacy of lowering dietary intake of total fat, saturated fat, and cholesterol in growing children and adolescents with severe hyperlipidemia. STUDY DESIGN: This is a 3-year follow-up study conducted on a sample of convenience at three pediatric referral centers in New York City and its suburbs. Subjects were 138 children and adolescents 2 to 15 years of age (54% male), who had been referred with a diagnosis of hyperlipidemia. Those selected had total serum cholesterol values greater than the 95th percentile for age and had at least three visits over 3 years. They were placed on diets restricting total fat content to 30% of total calories and saturated fat to 10% of total calories (National Cholesterol Education Program Step I diet). Anthropometric measures, lipid profiles, and dietary assessment were obtained at each visit. Anthropometric data were analyzed by sex and age. Z scores for height and weight were calculated from NHANES II data and were compared by paired t tests (Hamill et al., 1979, Am J Clin Nutr 32:607-29). RESULTS: Total serum cholesterol dropped from 262 mg/dL at baseline to 249 mg/dL at 3-year follow-up (P = 0.003). There was no significant change in height or weight percentile, expressed as Z score, from baseline to 3-year follow up. CONCLUSIONS: In this population the supervised dietary interventions resulted in a sustained improvement of the lipid profile, with no demonstrable adverse effect on growth.

The metabolic responses to starvation and refeeding in adolescents with anorexia nervosa.

Adaptive changes in metabolism result in decreased energy requirements in AN. A retrospective study of 21 hospitalized female AN patients demonstrated that indirect calorimetry (IC) measurement of resting energy expenditure (REE) was significantly lower than REE calculated by the Harris-Benedict equation (HBE). The HBE was adjusted by multiple-regression analysis to reflect the hypometabolic state of AN, and the adjusted equation was prospectively validated in 37 hospitalized female AN patients. Refeeding requires an understanding of both baseline requirements and metabolic changes that occur during nutritional rehabilitation. In our present study, we prospectively evaluated changes in fasting and postprandial REE in 50 hospitalized female patients meeting DSM-IV criteria for AN. Baseline IC measurements of fasting and postprandial REE were obtained within three days of admission, and every two weeks thereafter. Mean fasting REE increased significantly from 72 (+/-11.7) to 83.2 (+/-12.6) percent of predicted (p < 0.001) during the first two weeks of hospitalization. Likewise, postprandial REE also increased significantly from 17.5 (+/-18.2) to 27.9 (+/-15.9) percent above fasting REE during the same time period (p < 0.01). Significant increases in both REE and postprandial REE persisted in patients requiring longer hospitalizations. Despite the fact that prescribed energy intake and triiodothyronine (T3-RIA) levels increased during refeeding, there was no significant relationship between postprandial REE and energy intake or T3 levels after baseline. We conclude that energy metabolism in AN adapts to semistarvation by a reduction in fasting REE. With refeeding there is a reversal of this adaptive function, demonstrated by an increase in both fasting and postprandial energy expenditure. The increase in postprandial REE is not related to energy intake or thyroid function.

Resumption of menses in anorexia nervosa.

OBJECTIVE: To determine factors associated with resumption of menses (ROM) in adolescents with anorexia nervosa. DESIGN: Cohort study with 2-year follow-up. SETTING: Tertiary care referral center. PATIENTS: Consecutive sample of 100 adolescent girls with anorexia nervosa. INTERVENTIONS: Body weight, percent body fat, and luteinizing hormone, follicle-stimulating hormone, and estradiol levels were measured at baseline and every 3 months until ROM (defined as 2 or more consecutive spontaneous menstrual cycles). Treatment consisted of a combination of medical, nutritional, and psychiatric intervention aimed at weight gain and resolution of psychological conflicts. MAIN OUTCOME MEASURES: Body weight, body composition, and hormonal status at ROM. RESULTS: Menses resumed at a mean (+/-SD) of 9.4 +/- 8.2 months after patients were initially seen and required a weight of 2.05 kg more than the weight at which menses were lost. Mean (+/-SD) percent of standard body weight at ROM was 91.6% +/- 9.1%, and 86% of patients resumed menses within 6 months of achieving this weight. At 1-year follow-up, 47 (68%) of 69 patients had resumed menses and 22 (32%) remained amenorrheic. No significant differences were seen in body weight, body mass index, or percent body fat at follow-up in those who resumed menses by 1 year compared with those who had not. Subjects who remained amenorrheic at 1 year had lower levels of luteinizing hormone (P < .001) and follicle-stimulating hormone (P < .05) at baseline and lower levels of luteinizing hormone (P < .01) and estradiol (P < .001) at follow-up. At follow-up, a serum estradiol level of more than 110 pmol/L (30 pg/mL) was associated with ROM (relative risk, 4.6; 95% confidence interval, 1.9-11.2). CONCLUSIONS: A weight approximately 90% of standard body weight was the average weight at which ROM occurred and is a reasonable treatment goal weight, because 86% of patients who achieved this goal resumed menses within 6 months. Resumption of menses required restoration of hypothalamic-pituitary-ovarian function, which did not depend on the amount of body fat. Serum estradiol levels at follow-up best assess ROM.

Comparison of corneal epithelial wound healing after photorefractive and lamellar keratectomy.

BACKGROUND: The rate of corneal epithelial wound healing may be determined, in part, by the characteristics of the stromal surface. The excimer laser has the ability to produce a highly uniform ablated surface, which may facilitate reepithelialization after photorefractive keratectomy (PRK). METHODS: The rate of corneal epithelial wound healing after excimer laser PRK was compared with the rate of reepithelialization after manual lamellar keratectomy. Ten rabbits received a 4-mm diameter ablation in one eye (fluence = 160 mJ/cm2) and a shallow, 5-mm diameter, manual lamellar keratectomy in the contralateral eye. At 0, 4, 8, 12, 24, 36, 48, 60, and 72 hours after wounding, sodium fluorescein was instilled, and photographs were taken, converted to video images, and digitized. Wound area was calculated for each time point and converted to wound radius; the slopes of the wound radius, plotted over time, were compared to determine rates of healing. Scanning electron microscopy was performed immediately after wounding to examine surface regularity. RESULTS: By 24 hours after wounding, corneas that had undergone PRK demonstrated a significantly faster rate of epithelial wound healing compared with eyes that underwent lamellar keratectomy (33.4 +/- 1.9 microns/hr vs 27.8 +/- 1.4 microns/hr, respectively, for 12 to 72 hours) (p < 0.0001). Scanning electron microscopy showed greater stromal surface irregularity in the corneas that had undergone lamellar keratectomy, compared with the laser-ablated corneas. CONCLUSIONS: This study demonstrates that the rate of epithelial wound healing is significantly faster after excimer laser PRK than after lamellar keratectomy in the rabbit. Variations in surface regularity and wound edge profile may contribute to differences in wound healing.

Reversibility of cerebral ventricular enlargement in anorexia nervosa, demonstrated by quantitative magnetic resonance imaging.

OBJECTIVE: To determine the reversibility of the loss of brain parenchyma and ventricular enlargement in patients with anorexia nervosa after refeeding. STUDY DESIGN: Quantitative magnetic resonance imaging was performed on three groups of subjects: (1) 12 female adolescents hospitalized with anorexia nervosa, (2) the same 12 patients after nutritional rehabilitation, a mean of 11.1 months later, and (3) 12 healthy age-matched control subjects. Sixty-four contiguous coronal magnetic resonance images, 3.1 mm thick, were obtained. With a computerized morphometry system, lateral and third ventricular volumes were measured by a single observer unaware of the status of the patient. RESULTS: On admission, patients were malnourished and had lost an average of 11.7 kg (body mass index, 14.3 +/- 2.0 kg/m2). After refeeding, they gained an average of 9.7 kg (body mass index, 17.9 +/- 1.5 kg/m2). Total ventricular volume decreased from 17.1 +/- 5.5 cm3 on admission to 12.4 +/- 3.0 cm3 after refeeding (p < 0.01) and returned to the normal range. The degree of enlargement of the third ventricle was greater than that of the lateral ventricles. There was a significant inverse relationship between body mass index and total ventricular volume (r = -0.63; p < 0.05). CONCLUSION: In patients with anorexia nervosa, cerebral ventricular enlargement correlates with the degree of malnutrition and is reversible with weight gain during long-term follow-up.

Effects of dietary modification and fish oil supplementation on dyslipoproteinemia in pediatric systemic lupus erythematosus.

OBJECTIVE: To determine if a program of dietary modification and fish oil supplementation is effective in treating the dyslipoproteinemia in pediatric systemic lupus erythematosus (SLE). METHODS: Prospective clinical trial where each patient serves as his/her own control. Twenty-four consecutive adolescents fulfilling SLE classification criteria were screened with fasting lipid profiles. Patients were identified as having dyslipoproteinemia of active disease or of corticosteroid therapy. Patients were treated for 6 weeks with dietary modification and if dyslipoproteinemia did not normalize with another 6 weeks of dietary modification and fish oil supplementation. RESULTS: Seventeen patients (71%) had dyslipoproteinemia; 10 of active disease, 4 of steroid therapy; 3 with a combined pattern. Eleven patients underwent dietary modification. There was a significant decrease in serum triglyceride concentrations (p < 0.05). Total cholesterol, low density lipoprotein cholesterol, and high density lipoprotein cholesterol did not change significantly. A further significant decline in serum triglycerides was achieved with fish oil supplementation (p < 0.05). Five of the 11 patients who underwent treatment continued to have dyslipoproteinemia. CONCLUSION: Dyslipoproteinemia is common in pediatric SLE. Dietary modification and fish oil supplementation appear to be effective in improving serum lipid profiles, and blinded studies are warranted. a significant number of patients may require pharmacologic therapy for persistent dyslipoproteinemia to prevent complications of premature atherosclerosis.

Effect of lipoproteins on macrophage superoxide generation.

Superoxide production by macrophages and leukocytes may have an important role in atherogenesis. Whether lipoproteins modulate the superoxide production of these cells is not clear. Therefore, the effect of lipoproteins on the production of superoxide by rat peritoneal macrophages was tested. VLDL and LDL inhibited digitonin-stimulated superoxide production in a dose-dependent manner. Maximum inhibition was observed at 10 micrograms ml-1 of VLDL protein and 50 micrograms ml-1 of LDL protein respectively. In contrast, HDL (40 micrograms protein ml-1) enhanced digitonin-stimulated superoxide production (by 47 per cent). Macrophage superoxide production induced by arachidonic acid was enhanced by both VLDL (130 per cent) and HDL (84 per cent), whereas LDL had no effect. The lipoproteins had no effect on macrophage superoxide stimulated by other agonists such as phorbol myristate 13-acetate, sodium fluoride or the calcium ionophore, A23187. The effect of lipoproteins was also tested on human polymorphonuclear leukocyte superoxide generation, stimulated by digitonin and PMA. Ten micrograms of VLDL, 50 micrograms of LDL and 50 micrograms of HDL proteins ml-1, inhibited digitonin-induced superoxide production by 50, 100 and 33 per cent respectively. Lipoproteins had no effect on PMA stimulated superoxide generation by human polymorphonuclear leukocytes. The stimulatory and inhibitory effects of lipoproteins on macrophage and neutrophil superoxide generation could be important in the understanding of oxidation-mediated development of atherosclerosis.