Body mass index and nutritional intake following Elexacaftor/Tezacaftor/Ivacaftor modulator therapy in adults with cystic fibrosis.

BACKGROUND: Elexacaftor/Tezacaftor/Ivacaftor (ETI) modulator therapy is often associated with increased body mass index (BMI) in people with cystic fibrosis (CF). This is thought to reflect improved clinical stability and increased appetite and nutritional intake. We explored the change in BMI and nutritional intake following ETI modulator therapy in adults with CF. METHODS: Dietary intake, measured with myfood24®, and BMI were collected from adults with CF at baseline and follow-up as part of an observational study. Changes in BMI and nutritional intake in participants who commenced ETI therapy between time points were assessed. To contextualize findings, we also assessed changes in BMI and nutritional intake between study points in a group on no modulators. RESULTS: In the pre and post ETI threapy group (n = 40), BMI significantly increased from 23.0 kg/m2 (IQR 21.4, 25.3) at baseline to 24.6 kg/m2 (IQR 23.0, 26.7) at follow-up (p<0.001), with a median of 68 weeks between time points (range 20-94 weeks) and median duration of ETI therapy was 23 weeks (range 7-72 weeks). There was a significant decrease in energy intake from 2551 kcal/day (IQR 2107, 3115) to 2153 kcal/day (IQR 1648, 2606), p<0.001. In the no modulator group (n = 10), BMI and energy intake did not significantly change between time points (p>0.05), a median of 28 weeks apart (range 20-76 weeks). CONCLUSIONS: These findings tentatively suggest that the increase in BMI with ETI therapy may not simply be attributable to an increase in oral intake. Further exploration into the underlying aetiology of weight gain with ETI therapy is needed.

Mindfulness moderates the relationship between emotional eating and body mass index in a sample of people with cystic fibrosis.

PURPOSE: Self-regulation in eating is significant for enhancing life expectancy of people with cystic fibrosis (CF), but research with this population is scarce. METHODS: In a cross-sectional study, adults with CF completed a number of psychometric scales exploring typical eating behaviours that may increase calorific intake including motivations to eat palatable foods and scales that may be associated with decreased calorific intake: mindfulness, mindful eating and self-compassion. RESULTS: Findings suggested that motivations to eat palatable foods and eating behaviours correlate with higher BMI, while mindfulness, mindful eating and self-compassion did not reach significance. Mindfulness and mindful eating moderated the relationship between emotional eating and BMI, while self-compassion did not moderate this relationship. CONCLUSIONS: There is a need to develop healthy and effective means of enhancing calorific intake, where this is indicated, adapting mindful eating principles to focus on increasing both self-regulation and pleasure in eating while reducing emotional eating may be one means of doing this. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

The contribution of iron deficiency to the risk of peripartum transfusion: a retrospective case control study.

BACKGROUND: Iron deficiency in pregnancy is associated with inferior maternal and fetal outcomes. Postpartum depression, prematurity, intrauterine growth restriction, impaired childhood cognition and transfusion are all sequelae of maternal iron deficiency anemia. Transfusion to women of childbearing age has important consequences including increasing the risk of hemolytic disease of the fetus and newborn with future pregnancies. The relative contribution of iron deficiency to transfusion rates in the peripartum period is unknown. This study aimed to identify the prevalence of iron deficiency and anemia in pregnant women that received peripartum transfusions relative to age-matched non-transfused controls. METHODS: We performed a retrospective case-control study of all women that were transfused in the peripartum period from January, 2014 to July, 2018. Cases were compared to the next age matched control to deliver at our institution. The primary objective was to determine the proportion of patients with iron deficiency in pregnancy or anemia in pregnancy in cases and controls. Charts were reviewed for predisposing risk factors for iron deficiency, laboratory measures of iron deficiency and anemia, iron supplementation history and maternal and fetal outcomes. Factors associated with peripartum transfusion were analyzed using a multivariate logistic regression. RESULTS: 169 of 18, 294 (0.9%) women were transfused in the peripartum period and 64 (44%) of those transfused received 1 unit. Iron deficiency or anemia were present in 103 (71%) transfused women and 74 (51%) control women in pregnancy (OR 2.34, 95% CI: 3.7-18.0). Multivariate analysis identified social work involvement (adjusted OR 4.1, 95% CI: 1.8-10.1), intravenous iron supplementation in pregnancy (adjusted OR 3.8, 95% CI: 1.2-17.4) and delivery by unscheduled cesarean section (adjusted OR 2.8, 95% CI: 1.3-6.2) as significant predictors of peripartum transfusion. CONCLUSIONS: Pregnant women being followed by a social worker, receiving intravenous iron supplementation in pregnancy or who deliver by unscheduled cesarean section are more likely to receive a red blood cell transfusion. Women with iron deficiency or anemia in pregnancy are at increased risk of peripartum blood transfusions and warrant early and rigorous iron supplementation.

Is there a causal relationship between vitamin D and melanoma risk? A Mendelian randomization study.

BACKGROUND: Several preclinical studies have identified the antiproliferative effects of 25-hydroxyvitamin D [25(OH)D; vitamin D]. Ultraviolet radiation (UVR) is essential for vitamin D synthesis yet increases the risk of melanoma. Observational studies on the association of vitamin D levels with melanoma risk have reported inconclusive results, and are difficult to interpret owing to the potential confounding from the dual role of UVR. OBJECTIVES: To determine whether there is a causal association between genetically predicted 25(OH)D concentrations and melanoma using a Mendelian randomization (MR) approach. METHODS: We performed MR using summary data from a large genome-wide association study (GWAS) meta-analysis of melanoma risk, consisting of 12 874 cases and 23 203 controls. Five single nucleotide polymorphisms associated with 25(OH)D concentration - rs12785878, rs10741657, rs2282679, rs6013897 and rs116970203 - were selected as instrumental variables. An inverse variance weighted method was used to access the evidence for causality. MR results from the melanoma meta-analysis were combined with results from an MR study based on a melanoma risk GWAS using UK Biobank data. RESULTS: A 20 nmol L-1 decrease in 25(OH)D was not associated with melanoma risk [odds ratio (OR) 1·06, 95% confidence interval (CI) 0·95-1·19]. Results from the UK Biobank were concordant with this, with meta-analysis of our and UK Biobank-derived MR causal estimates showing no association (OR 1·02, 95% CI 0·92-1·13 for a 20 nmol L-1 decrease). CONCLUSIONS: The results suggest that vitamin D levels may not be causally associated with the risk of melanoma. What's already known about this topic? Antitumour activity of vitamin D has been identified in preclinical studies. Observational studies link vitamin D deficiency with an increased risk of a range of cancers. There is a growing public interest for vitamin D supplementation. Observational studies of melanoma are fraught with difficulties because while higher ultraviolet radiation levels increase vitamin D levels, such exposure is also associated with increased melanoma risk. Results from observational studies are inconclusive regarding the effect of vitamin D on melanoma risk. What does this study add? Using Mendelian randomization, an approach to causal inference, which is analogous to a natural randomized controlled trial, we found no causal association between vitamin D levels and melanoma.

Factors influencing the late phase of recovery after bone mineral density loss in allogeneic stem cell transplantation survivors.

Accelerated bone mineral density loss (BMDL) occurs early after allogeneic stem cell transplantation (SCT) and is related to factors such as steroids and chronic GvHD. In order to understand the natural history of BMDL of SCT in the longer term, we evaluated a longitudinal cohort of 148 survivors with a median follow-up of 12 years (range 3-22 years). All women received hormone replacement therapy, and routine calcium/vitamin D supplementation was recommended but ∼50% of patients still had suboptimal vitamin D levels and bisphosphonates were rarely utilized. BMD significantly improved from 5 to 20+ years but the femoral neck and forearm remained vulnerable sites. Younger age, higher pretransplant body mass index (BMI) and increment in BMI post transplant were significantly associated with increased BMD and protected against osteopenia/osteoporosis. These findings support consideration of BMD loss in SCT survivors in two phases, an early phase of BMD loss (3-5 years) followed by a later phase of BMD recovery, with different protective and aggravating factors. Treatment- and transplant-related factors (such as steroids, immunosuppressives, chronic GvHD, vitamin D) are known to impact the early phase of BMD loss but age and BMI are more influential in the late phase of BMD recovery.

A store-operated calcium channel inhibitor attenuates collagen-induced arthritis.

BACKGROUND AND PURPOSE: Store-operated calcium (SOC) channels are thought to play a critical role in immune responses, inflammatory diseases and chronic pain. The aim of this study was to explore the potential role and mechanisms of SOC channels in collagen-induced arthritis (CIA). EXPERIMENTAL APPROACH: The CIA mouse model was used to examine the effects of the SOC channel inhibitor YM-58483 on CIA and arthritic pain. Hargreaves' and von Frey hair tests were conducted to measure thermal and mechanical sensitivities of hind paws. elisa was performed to measure cytokine production, and haematoxylin and eosin staining was used to assess knee histological changes. Western blot analysis was performed to examine protein levels. KEY RESULTS: Pretreatment with 5 or 10 mg · kg(-1) of YM-58483 reduced the incidence of CIA, prevented the development of inflammation and pain hypersensitivity and other signs and features of arthritis disease. Similarly, treatment with YM-58483 after the onset of CIA: (i) reversed the clinical scores; (ii) reduced paw oedema; (iii) attenuated mechanical and thermal hypersensitivity; (iv) improved spontaneous motor activity; (v) decreased periphery production of IL-1ß, IL-6 and TNF-α; and (vi) reduced spinal activation of ERK and calmodulin-dependent PKII (CaMKIIα). CONCLUSIONS AND IMPLICATIONS: This study provides the first evidence that inhibition of SOC entry prevents and relieves rheumatoid arthritis (RA) and arthritic pain. These effects are probably mediated by a reduction in cytokine levels in the periphery and activation of ERK and CaMKIIα in the spinal cord. These results suggest that SOC channels are potential drug targets for the treatment of RA.

Endothelial vacuolization induced by highly permeable silicon membranes.

Assays for initiating, controlling and studying endothelial cell behavior and blood vessel formation have applications in developmental biology, cancer and tissue engineering. In vitro vasculogenesis models typically combine complex three-dimensional gels of extracellular matrix proteins with other stimuli like growth factor supplements. Biomaterials with unique micro- and nanoscale features may provide simpler substrates to study endothelial cell morphogenesis. In this work, patterns of nanoporous, nanothin silicon membranes (porous nanocrystalline silicon, or pnc-Si) are fabricated to control the permeability of an endothelial cell culture substrate. Permeability on the basal surface of primary and immortalized endothelial cells causes vacuole formation and endothelial organization into capillary-like structures. This phenomenon is repeatable, robust and controlled entirely by patterns of free-standing, highly permeable pnc-Si membranes. Pnc-Si is a new biomaterial with precisely defined micro- and nanoscale features that can be used as a unique in vitro platform to study endothelial cell behavior and vasculogenesis.

Physicians' attitudes about multiplex tumor genomic testing.

PURPOSE: Although predictive multiplex somatic genomic tests hold the potential to transform care by identifying targetable alterations in multiple cancer genes, little is known about how physicians will use such tests in practice. PARTICIPANTS AND METHODS: Before the initiation of enterprise-wide multiplex testing at a major cancer center, we surveyed all clinically active adult cancer physicians to assess their current use of somatic testing, their attitudes about multiplex testing, and their genomic confidence. RESULTS: A total of 160 physicians participated (response rate, 61%): 57% were medical oncologists; 29%, surgeons; 14% radiation oncologists; 37%, women; and 83%, research principal investigators. Twenty-two percent of physicians reported low confidence in their genomic knowledge. Eighteen percent of physicians anticipated testing patients infrequently (≤ 10%), whereas 25% anticipate testing most patients (≥ 90%). Higher genomic confidence was associated with wanting to test a majority of patients (adjusted odds ratio [OR], 6.09; 95% CI, 2.1 to 17.5) and anticipating using actionable (adjusted OR, 2.46; 95% CI, 1.2 to 5.2) or potentially actionable (adjusted OR, 2.89; 95% CI, 1.1 to 7.9) test results to inform treatment recommendations. Forty-two percent of physicians endorsed disclosure of uncertain genomic findings to patients. CONCLUSION: Physicians at a tertiary-care National Cancer Institute-designated comprehensive cancer center varied considerably in how they planned to incorporate predictive multiplex somatic genomic tests into practice and in their attitudes about the disclosure of genomic information of uncertain significance. Given that many physicians reported low genomic confidence, evidence-based guidelines and enhanced physician genomic education efforts may be needed to ensure that genomically guided cancer care is adequately delivered.

Enuresis and more.

We describe Pervasive Refusal Syndrome, an important but rare, debilitating condition that may present to paediatric services. Although previous reports have described improvement seen with care delivered in the mental health setting, we have demonstrated treatment predominately delivered in a paediatric ward environment associated with successful recovery.

Treatment of new-onset ulcerative colitis and ulcerative proctitis: a retrospective study.

BACKGROUND: Although guidelines recommend use of oral 5-aminosalicylates (5-ASAs) as first-line therapy in patients with mild to moderate ulcerative colitis (UC) and ulcerative proctitis (UP) and steroids with or without 5-ASAs in those more severely ill, little is known about how UC and UP are actually treated. AIM: To document treatment of new-onset UC and UP in routine clinical practice. METHODS: Using a large US health insurance database, we identified all persons with new-onset UC or UP between 1 January 2005 and 31 December 2007, based on: (i) initial receipt of an oral 5-ASA, mesalazine (mesalamine) suppository, 5-ASA enema, steroid, antimetabolite, budesonide or TNF inhibitor; (ii) sigmoidoscopy/colonoscopy in prior 30 days resulting in a new diagnosis of UC or UP and (iii) no prior encounters for Crohn's disease. We examined patterns of pharmacotherapy over 1 year. RESULTS: We identified 1516 UC patients and 636 UP patients who met study entry criteria. In UC, initial therapies most frequently used were oral 5-ASAs (53% of patients), oral 5-ASAs and systemic steroids (12%), systemic steroids (8%) and mesalazine suppositories (6%); in UP, mesalazine suppositories (42%) and oral 5-ASAs (19%) were most often used, followed by combination therapy (14%), mesalazine enema (11%) and rectal steroids (10%). Few patients received maintenance therapy, and there was limited use of antimetabolites and biological agents. CONCLUSIONS: Oral 5-ASAs and systemic steroids are the mainstay of treatment in patients with new-onset ulcerative colitis; in those with new-onset ulcerative proctitis, it is mesalazine suppositories. Care of these patients appears consistent with treatment guidelines.

Biomarkers of Oxidative Stress Study IV: ozone exposure of rats and its effect on antioxidants in plasma and bronchoalveolar lavage fluid.

The objective of this study was to determine whether acutely exposing rats to ozone would result in the loss of antioxidants from plasma and bronchoalveolar lavage fluid (BALF). Additional goals were to compare analyses of the same antioxidant concentration between different laboratories, to investigate which methods have the sensitivity to detect decreased levels of antioxidants, and to identify a reliable measure of oxidative stress in ozone-exposed rats. Male Fisher rats were exposed to either 2.0 or 5.0 ppm ozone inhalation for 2h. Blood plasma and BALF samples were collected 2, 7, and 16 h after the exposure. It was found that ascorbic acid in plasma collected from rats after the higher dose of ozone was lower at 2h, but not later. BALF concentrations of ascorbic acid were decreased at both 2 and 7h postexposure. Tocopherols (α, δ, γ), 5-nitro-γ-tocopherol, tocol, glutathione (GSH/GSSG), and cysteine (Cys/CySS) were not decreased, regardless of the dose or postexposure time point used for sample collection. Uric acid was significantly increased by the low dose at 2h and the high dose at the 7h point, probably because of the accumulation of blood plasma in the lung from ozone-increased alveolar capillary permeability. We conclude that measurements of antioxidants in plasma are not sensitive biomarkers for oxidative damage induced by ozone and are not a useful choice for the assessment of oxidative damage by ozone in vivo.

The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters.

OBJECTIVE: Sports-related concussion has received increasing attention as a cause of short- and long-term neurologic symptoms among athletes. The King-Devick (K-D) test is based on measurement of the speed of rapid number naming (reading aloud single-digit numbers from 3 test cards), and captures impairment of eye movements, attention, language, and other correlates of suboptimal brain function. We investigated the K-D test as a potential rapid sideline screening for concussion in a cohort of boxers and mixed martial arts fighters. METHODS: The K-D test was administered prefight and postfight. The Military Acute Concussion Evaluation (MACE) was administered as a more comprehensive but longer test for concussion. Differences in postfight K-D scores and changes in scores from prefight to postfight were compared for athletes with head trauma during the fight vs those without. RESULTS: Postfight K-D scores (n = 39 participants) were significantly higher (worse) for those with head trauma during the match (59.1 ± 7.4 vs 41.0 ± 6.7 seconds, p < 0.0001, Wilcoxon rank sum test). Those with loss of consciousness showed the greatest worsening from prefight to postfight. Worse postfight K-D scores (r(s) = -0.79, p = 0.0001) and greater worsening of scores (r(s) = 0.90, p < 0.0001) correlated well with postfight MACE scores. Worsening of K-D scores by ≥5 seconds was a distinguishing characteristic noted only among participants with head trauma. High levels of test-retest reliability were observed (intraclass correlation coefficient 0.97 [95% confidence interval 0.90-1.0]). CONCLUSIONS: The K-D test is an accurate and reliable method for identifying athletes with head trauma, and is a strong candidate rapid sideline screening test for concussion.

Treatment of urinary incontinence after stroke in adults.

BACKGROUND: Urinary incontinence can affect 40-60% of people admitted to hospital after a stroke, with 25% still having problems on hospital discharge and 15% remaining incontinent at one year. OBJECTIVES: To determine the optimal methods for treatment of urinary incontinence after stroke in adults. SEARCH STRATEGY: We searched the Cochrane Incontinence and Stroke Groups specialised registers (searched 15 March 2007 and 5 March 2007 respectively), CINAHL (January 1982 to January 2007), national and international trial databases for unpublished data, and the reference lists of relevant articles. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating the effects of interventions designed to promote continence in people after stroke. DATA COLLECTION AND ANALYSIS: Data extraction and quality assessment were undertaken by two reviewers working independently. Disagreements were resolved by a third reviewer. MAIN RESULTS: Twelve trials with a total of 724 participants were included in the review. Participants were from a mixture of settings, age groups and phases of stroke recovery. BEHAVIOURAL INTERVENTIONS: Three trials assessed behavioural interventions, such as timed voiding and pelvic floor muscle training. All had small sample sizes and confidence intervals were wide. SPECIALISED PROFESSIONAL INPUT INTERVENTIONS: Two trials assessed variants of professional input interventions. Results tended to favour the intervention groups: in a small trial in early rehabilitation, fewer people had incontinence at discharge from hospital after structured assessment and management than in a control group (1/21 vs. 10/13; RR 0.06, 95% CI 0.01 to 0.43); in the second trial, assessment and management by Continence Nurse Advisors was associated with fewer participants having urinary symptoms (48/89 vs. 38/54; RR 0.77, 95% CI 0.59 to 0.99) and statistically significantly more being satisfied with care. COMPLEMENTARY THERAPY INTERVENTIONS: Three small trials all reported fewer participants with incontinence after acupuncture therapy (overall RR 0.44; 95% 0.23 to 0.86), but there were particular concerns about study quality. PHARMACOTHERAPY AND HORMONAL INTERVENTIONS: There were three small trials that included groups allocated meclofenoxate, oxybutinin or oestrogen. There were no apparent differences other than in the trial of meclofenoxate where fewer participants had urinary symptoms in the active group than in the control group (9/40 vs. 27/40; RR 0.33, 95% CI 0.18 to 0.62). AUTHORS' CONCLUSIONS: Data from the available trials are insufficient to guide continence care of adults after stroke. However, there was suggestive evidence that professional input through structured assessment and management of care and specialist continence nursing may reduce urinary incontinence and related symptoms after stroke. Better quality evidence is required of the range of interventions that have been suggested for continence care after stroke.

Extreme obesity reduces bone mineral density: complementary evidence from mice and women.

OBJECTIVE: To evaluate the effects of body adiposity on bone mineral density in the presence and absence of ovarian hormones in female mice and postmenopausal women. RESEARCH METHODS AND PROCEDURES: We assessed percentage body fat, serum leptin levels, and bone mineral density in ovariectomized and non-ovariectomized C57BL/6 female mice that had been fed various calorically dense diets to induce body weight profiles ranging from lean to very obese. Additionally, we assessed percentage body fat and whole body bone mineral density in 37 overweight and extremely obese postmenopausal women from the Women's Contraceptive and Reproductive Experiences study. RESULTS: In mice, higher levels of body adiposity (>40% body fat) were associated with lower bone mineral density in ovariectomized C57BL/6 female mice. A similar trend was observed in a small sample of postmenopausal women. DISCUSSION: The complementary studies in mice and women suggest that extreme obesity in postmenopausal women may be associated with reduced bone mineral density. Thus, extreme obesity (BMI > 40 kg/m2) may increase the risk for osteopenia and osteoporosis. Given the obesity epidemic in the U.S. and in many other countries, and, in particular, the rising number of extremely obese adult women, increased attention should be drawn to the significant and interrelated public health issues of obesity and osteoporosis.

Energy balance and carcinogenesis: underlying pathways and targets for intervention.

The prevalence of obesity, an established epidemiologic risk factor for many cancers, has risen steadily for the past several decades in the U.S. Particularly alarming are the increasing rates of obesity among children, portending continuing increases in the rates of obesity and obesity-related cancers for many years to come. Unfortunately, the mechanisms underlying the association between obesity and cancer are not well understood. In particular, the effects and mechanistic targets of interventions that modulate energy balance, such as reduced calorie diets and physical activity, on the carcinogenesis process have not been well characterized. The purpose of this review is to provide a strong foundation for future mechanistic-based research in this area by describing key animal and human studies of energy balance modulations involving diet, exercise, or pharmaceutical agents and by focusing on the interrelated pathways affected by alterations in energy balance. Particular attention in this review is placed on the components of the insulin/IGF-1/Akt pathway, which has emerged as a predominant target for disrupting the obesity-cancer link. Also discussed is the promise of global approaches, including genomics, proteomics, and metabolomics, for the elucidation of energy balance-responsive pathways. The ultimate goal of this work is to provide the missing mechanistic information necessary to identify targets for the prevention and control of cancers related to or caused by excess body weight.

Prevention and treatment of urinary incontinence after stroke in adults.

BACKGROUND: Urinary incontinence can affect 40-60% of people admitted to hospital after a stroke, with 25% still having problems on hospital discharge and around 15% remaining incontinent at one year. OBJECTIVES: To determine the optimal methods for prevention and treatment of urinary incontinence after stroke in adults. SEARCH STRATEGY: We searched the Cochrane Incontinence and Stroke Groups specialised registers (searched 15 December 2004 and 26 October 2004, respectively), CINAHL (January 1982 to November 2004), national and international trial databases for unpublished data, and the reference lists of relevant articles. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials evaluating the effects of interventions designed to promote continence in people after stroke. DATA COLLECTION AND ANALYSIS: Data extraction and quality assessment were undertaken by two reviewers working independently. Disagreements were resolved by a third reviewer. MAIN RESULTS: Seven trials with a total of 399 participants were included in the review. Participants were from a mixture of settings, age groups and phases of stroke recovery. No two trials addressed the same comparison. Four trials tested an intervention against usual care, including acupuncture, timed voiding, and two types of specialist professional intervention. One cross-over trial tested an intervention (oestrogen) against placebo. One trial tested a specific intervention (oxybutynin) against another intervention (timed voiding), and one trial tested a combined intervention (sensory-motor biofeedback plus timed voiding) against a single component intervention (timed voiding alone). Reported data were insufficient to evaluate acupuncture or timed voiding versus usual care, oxybutynin versus timed voiding, or sensory motor biofeedback plus timed voiding versus usual care. Evidence from a single small trial suggested that structured assessment and management of care in early rehabilitation may reduce the number of people with incontinence at hospital discharge (1/21 versus 10/13; RR 0.06, 95% CI 0.01 to 0.43), and have other benefits. Evidence from another trial suggested that assessment and management of care by Continence Nurse Practitioners in a community setting may reduce the number of urinary symptoms (48/89 versus 38/54; RR 0.77, 95% CI 0.59 to 0.99), and increase satisfaction with care. AUTHORS' CONCLUSIONS: There was suggestive evidence that specialist professional input through structured assessment and management of care and specialist continence nursing may reduce urinary incontinence after stroke. Data from trials of other physical, behavioural, complementary and anticholinergic drug interventions are insufficient to guide continence care of adults after stroke.

Biomarkers of oxidative stress study II: are oxidation products of lipids, proteins, and DNA markers of CCl4 poisoning?

Oxidation products of lipids, proteins, and DNA in the blood, plasma, and urine of rats were measured as part of a comprehensive, multilaboratory validation study searching for noninvasive biomarkers of oxidative stress. This article is the second report of the nationwide Biomarkers of Oxidative Stress Study using acute CCl4 poisoning as a rodent model for oxidative stress. The time-dependent (2, 7, and 16 h) and dose-dependent (120 and 1200 mg/kg i.p.) effects of CCl4 on concentrations of lipid hydroperoxides, TBARS, malondialdehyde (MDA), isoprostanes, protein carbonyls, methionine sulfoxidation, tyrosine products, 8-hydroxy-2'-deoxyguanosine (8-OHdG), leukocyte DNA-MDA adducts, and DNA-strand breaks were investigated to determine whether the oxidative effects of CCl4 would result in increased generation of these oxidation products. Plasma concentrations of MDA and isoprostanes (both measured by GC-MS) and urinary concentrations of isoprostanes (measured with an immunoassay or LC/MS/MS) were increased in both low-dose and high-dose CCl4-treated rats at more than one time point. The other urinary markers (MDA and 8-OHdG) showed significant elevations with treatment under three of the four conditions tested. It is concluded that measurements of MDA and isoprostanes in plasma and urine as well as 8-OHdG in urine are potential candidates for general biomarkers of oxidative stress. All other products were not changed by CCl4 or showed fewer significant effects.

Stoichiometry-dependent formation of quantum dot-antibody bioconjugates: a complementary atomic force microscopy and agarose gel electrophoresis study.

The unique advantages of quantum dot (QD) bioconjugates have motivated their application in biological assays. However, physical characterization of bioconjugated QDs after surface modification has often been overlooked. Here, biotinylated antibodies (biotin-IgG) were attached to commercial streptavidin-conjugated quantum dots (strep-QDs) at different stoichiometric ratios, and these QD bioconjugates were characterized with atomic force microscopy and discontinuous sodium dodecyl sulfate agarose gel electrophoresis (SDS-AGE). The results from these complementary analytical techniques showed that the molar ratio determined the relative sizes, molecular weights and morphologies of the QD bioconjugates. Additionally, the novel discontinuous SDS-AGE analysis confirmed specific binding between biotin-IgG and strep-QDs. Researchers who design QD bioconjugates for cell-based assays should consider stoichiometry-dependent differences in the physical properties of their QD bioconjugates.

Role of leptin in modulating the hypothalamic-pituitary axis and luteinizing hormone secretion in the prepuberal gilt.

Three experiments (EXP) were conducted to test the hypothesis that leptin modulates LH, GnRH, and neuropeptide Y (NPY) secretion. In EXP I, prepuberal gilts received intracerebroventricular (i.c.v.) leptin injections and blood samples were collected. In EXP II, anterior pituitary cells from prepuberal gilts in primary culture were challenged with 10(-14), 10(-13), 10(-12), 10(-11), 10(-10), 10(-9), 10(-8), 10(-7), or 10(-6) M leptin individually or in combinations with 10(-10), 10(-9), and 10(-8) M GnRH. In EXP III, hypothalamic-preoptic area (HYP-POA) explants were placed in perfusion system and exposed to 0 (n=5), 10(-12) M (n=4), 10(-10) M (n=4), 10(-8) M (n=4), or 10(-6) M (n=5) human recombinant leptin (LEP) for 30 min. In EXP I, serum LH concentrations were unaffected by leptin treatment. In EXP II, all doses of leptin increased LH secretion except for 10(-12) and 10(-7) M. Only 10(-7), or 10(-13) M leptin in combination with 10(-8) or 10(-9) M GnRH, respectively, suppressed LH secretion. In EXP III, prior to leptin, media GnRH concentrations were similar across treatments. Media GnRH concentrations increased after 10(-12), 10(-10), and 10(-8) M leptin compared to control. Leptin treatment failed to influence NPY secretion across treatments. These results indicate that components of the neuroendocrine axis that regulate GnRH and LH secretion are functional and leptin sensitive before the onset of puberty. Other neural peptides in addition to NPY may mediate the acute effects of leptin on the GnRH-LH system and lastly, the inability of i.c.v. leptin treatment to increase LH secretion may in part be related to stage of sexual maturation and associated change in negative feedback action of estradiol on LH secretion.