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PubMed1986

Scanning spectrophotometry for the dynamic study of tissue respiration in intact organs.

For use with intact perfused organs a spectrophotometer system has been developed, both for dual-wavelength absorption measurements and for spectral scanning. A monochromator is used for illumination and scanning in the visible and near infrared. Optic fibres conduct light to the specimen under examination and from the specimen to a detecting photomultiplier. System control is exercised by a microcomputer, which also processes the collected data. The performance of the system on isolated perfused rat heart is demonstrated, in the spectral scanning mode and in the dual-wavelength mode, by studying simultaneously the kinetics of cytochrome aa3, and myoglobin oxidation-reduction.

Animals↗

PubMed2003

Nutrition in hemodialysis patients previously on a supplemented very low protein diet.

BACKGROUND: Nutritional safety of protein-restricted diets in patients with chronic renal failure is controversial. In the present study, we have assessed the evolution of nutritional status after initiation of hemodialysis in patients previously treated by a supplemented very low protein diet (SVLPD). METHODS: Nutritional data were prospectively collected during the first year of hemodialysis from 15 consecutive patients treated with a SVLPD (0.3 g protein/kg/day supplemented with essential amino acids, calcium, iron, and vitamins) and compared to 15 age- and gender-matched end-stage renal disease (ESRD) patients previously on a less-restricted diet (0.90 +/- 0.21 g protein/kg/day) who started hemodialysis during the same period. Dual-energy x-ray absorptiometry (DEXA) was used to assess body composition at 0, 6, and 12 months. Hemodialysis prescriptions, biologic data and 3-day food records were collected every 3 months. RESULTS: Protein intake was higher than 1.2 g/kg/day in both groups as soon as 3 months after the start of hemodialysis. Albumin and prealbumin increased significantly during the first 6 months in all patients. Body mass index (BMI) increased in all patients (+0.97 +/- 1.31 kg/m2; P < 0.001) reflecting a gain in fat mass in the overall population (+2.36 +/- 2.94 kg/m2; P < 0.001) while lean body mass remained stable overall. CONCLUSION: Once on hemodialysis, SVLPD patients rapidly increased protein intake. Nutritional status improved in all patients, with a gain in fat mass in all, and a gain in lean body mass in SVLPD men only. These data indicate that treatment with a SVLPD prior to hemodialysis initiation is nutritionally safe.

Absorptiometry, Photon↗

PubMed2006

NNK activates ERK1/2 and CREB/ATF-1 via beta-1-AR and EGFR signaling in human lung adenocarcinoma and small airway epithelial cells.

We have shown that the tobacco nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is an agonist for -adrenergic receptors (beta-ARs) and increased DNA synthesis of human lung adenocarcinoma cells with features of bronchiolar Clara cells by binding to these receptors. Using a cell line derived from a human pulmonary adenocarcinoma with Clara cell phenotype (PACC) and immortalized human small airway epithelial cells (HPLD1), the putative cells of origin of this cancer type, our current studies have analyzed signaling initiated by binding of NNK to the beta 1-AR. NNK upregulated ERK1/2 and CREB/ATF-1 phosphorylation in a PKA-dependent manner in both cell lines. This response was further increased by transient overexpression of the beta 1-AR. Pre-exposure of cells to the selective beta 1-AR antagonist, atenolol, attenuated the stimulatory effects of NNK, suggesting the latter upregulated ERK1/2 and CREB/ATF-1 via this receptor. In vivo labeling and immunoprecipitation assays revealed that NNK phosphorylated the epidermal growth factor receptor (EGFR) at tyrosine residues, 991, 1068 and 1173, an effect inhibited by atenolol. The inhibitor of EGFR-specific tyrosine kinases, AG1478, reduced NNK ability to stimulate ERK1/2 and CREB/ATF-1. Genomic analysis of the exons 18-21 of the EGFR genes showed that no mutations were present in either gene. Collectively, our data provide evidence, for the first time, that NNK targets ERK1/2 and CREB/ATF-1 proteins via dual signaling involving beta 1-AR and EGFR pathways in PACCs and their putative cells of origin.

Activating Transcription Factor 1↗

PubMed2025

Prevalence and predictors of low bone mineral density in pediatric inflammatory bowel disease.

OBJECTIVES: Bone health is at risk in children with inflammatory bowel disease (IBD). This study examined the prevalence and predictors of low bone mineral density (BMD) in a cohort of children and young adults with IBD. METHODS: This single-center retrospective study included patients with IBD, ages 3.5-22 years, with completed dual x-ray absorptiometry (DXA) scans from 2006 to 2019. Demographic, clinical, and laboratory data were collected. Logistic regression analysis identified predictors associated with low BMD (Z-scores ≤ -2 standard deviations [SDs]) for three outcomes. In an overlapping IBD cohort with available genetic data between 2002 and 2019 (n = 378), genetic risk for diminished bone health was calculated using published polygenic risk scores generated from genome-wide association studies based on DXA or heel ultrasound speed of sound (SOS). Linear regression analysis examined associations of low BMD and genetic risk. RESULTS: Low BMD prevalence was 7% in our cohort (n = 600) based on spine bone mineral apparent density (BMAD), which best accounts for growth delays. Median (interquartile range [IQR]) spine BMAD Z-score was -0.37 SD (-1.11 to 0.35). Predictors of low BMAD included lower BMI Z-score (odds ratio [OR]: 0.67, p value: 0.02) and decreased height Z-score (OR: 0.6, p value: 0.005). Of those with longitudinal data (n = 118), low BMI (OR: 0.44, p value: <0.001) and steroid use (OR: 3.42, p value: 0.01) were associated with suboptimal bone health (Z-scores ≤ -1SD). In the cohort with genetic data, heel genomic SOS (β [standard error] = 0.17 [0.35], p ≤ 0.01) was associated with BMD. CONCLUSIONS: Lower BMI should prompt DXA monitoring in pediatric IBD. Genetic predisposition may identify an at-risk subpopulation.

Humans↗

PubMed2005

Osteoporosis in Parkinson's disease.

There are few studies of osteoporosis in Parkinson's disease (PD). We assessed the prevalence of osteoporosis in a PD clinic cohort. All subjects with a confirmed diagnosis of PD attending a clinic were invited to participate. All consenting subjects had bone density measured by dual energy X-ray absorptiometry scanning. Further data, including demography, disease duration, and disease severity, were collected. One hundred five subjects participated; median age was 75 (54-92) years. Fifty-one (49%) patients were men. Of the men: median T score, -1.3 (range, -4.7 to 3.8); median Z score, 0.0 (-3.2 to 4.7); diagnostic categories: osteoporosis, 20%; osteopenia, 41%; normal, 39%. Of the women: median T score -2.7 (-4.7 to 1.4); median Z score, -0.25 (-2.6 to 4.2); diagnostic categories: osteoporosis, 63%; osteopenia, 28%; and normal, 9%. Whole sample: osteoporosis, 42%; osteopenia, 34%; and normal, 24%. There were associations between age, depression, disease duration, and osteoporosis but not with disease severity. Female gender was an independent predictor of osteoporosis. The prevalence of osteoporosis/osteopenia is considerable in PD patients but does not exceed that of other people of similar age. Osteoporosis/osteopenia was present in almost all women of this age group with PD.

Age Factors↗

PubMed1987

The effects of anterior hypothalamic deafferentation on FSH-releasing activity in the intact female hamster.

To study the role of the anterior hypothalamic area (AHA) in the control of the estrous (E) rise of follicle stimulating hormone (FSH), female hamsters were subjected to anterior hypothalamic deafferentation (D) or sham deafferentation (S) on 1500 h of proestrus (P). Serum levels of FSH and luteinizing hormone (LH) were measured by radioimmunoassay and FSH and LH releasing activities measured by bioassay in the anterior (AH) and medial basal hypothalamus (MBH) at several time periods during P and E. D did not affect serum levels of LH, whereas there was an attenuation of FSH levels during P and E. D caused an increase in FSH releasing activity in the AH within 1 h, while LH releasing activity was elevated 8 h after D. In animals with D, LH releasing activity in the MBH was elevated during P and was similar to controls during E. FSH releasing activity in the MBH increased during early E and dropped precipitously by 1400 h of E. Collectively, these data demonstrate dichotomous changes in FSH and LH releasing activities and provide further evidence for dual control mechanisms for these two gonadotropins.

Animals↗

PubMed1996

Long-term effects of gastric transposition in children: a physiological study.

Gastric transposition (GT) has become a reliable alternative operation for oesophageal replacement in children. The aims of this study were to assess the long-term results of the operation and to study the function of the intrathoracic stomach. Current symptoms were assessed using a questionnaire and linear analogue scales. Lung function was measured using spirometry and plethysmography, and the results were corrected for height and expressed as a percentage of the predicted values for normal children. Gastric emptying was assessed using a dual isotope radiolabelled test meal (incorporating solid and liquid phases). Full anthropometric and haematologic data also were collected. The results are expressed as medians and interquartile ranges. Seventeen children were examined at least 5 years after GT; the median age was 9 years. Two children frequently had symptoms during swallowing. Four children had significant diarrhoeal episodes, and two had significant postprandial weakness or dizziness. Unexplained breathlessness was noted by four children. All but one child had lung function values that were lower than the mean predicted value for height. For example, the total lung capacity was 68%, and forced vital capacity (FVC) was 64%. However, the ratio of forced expiratory volume in 1 second (FEV1) to FVC was normal. The gastric emptying study showed that the intrathoracic stomach in all subjects served as a conduit (rather than a reservoir) for both liquids and solids. Rapid emptying (> 50%) in both phases occurred within 5 minutes of ingestion in 82% of the group. Thirteen children were between the 3rd and 97th percentiles for height, and 11 in this range for weight. Five children were anaemic (< 11.5 g/dL). In 11 of the tested samples, the serum ferritin was low, indicating depleted iron stores. GT is compatible with an entirely normal life and has allowed satisfactory growth and nutrition for the majority of subjects in this study group.

Anastomosis, Surgical↗

PubMed2002

Factors influencing efficient production of transgenic rabbits.

Factors that influence the efficient production of transgenic rabbits are described. The effects of the number of embryos transferred to the recipient, of recipient age, of a variety of gene constructs and of a dual use of donors as recipients (donor-recipient (DR) method) were statistically evaluated from the data collected in three experiments with three different genes. Higher survival rates of microinjected embryos were obtained in younger recipients (6-17 months), while the rates were-markedly decreased in recipients over 18 months old. Integration efficiencies (transgenic rabbits per newborn) were significantly different from the gene constructs used, but not related to either the number of embryos transferred or the number of newborns obtained. No significant differences in the survival rate of embryos of injected embryos and the integration efficiency were observed in both the DR embryo transfer method and the traditional method using pseudopregnant recipients (PR). Our results suggest that the gene construct and the survival rate of injected embryos were important factors affecting the efficiency of producing transgenic rabbits, and the age of recipients was one of the important factors affecting the survival rate of the injected embryos. The DR method was useful for reducing the number of animals required for production of transgenic rabbits.

Aging↗

PubMed1998

Outcomes of obese children and adolescents enrolled in a multidisciplinary health program.

OBJECTIVE: The study was designed to evaluate the impact of a multidisciplinary program on children and adolescents' weight control. DESIGN: Retrospective study regarding changes in relative weight of all patients treated regularly in an out-patient care public service between January 1992 and December 1993. SUBJECTS: 198 children and adolescents (108 girls and 90 boys; mean age: 9.25y; mean body mass index (BMI): 24.26 kg/m2, range 19.1-40.31). MEASUREMENTS: Anthropometric data collected at the visits were obtained until June 30 1994. BMI compared to reference data was used. Dual Photon X-ray Absorptiometry (DEXA) was used for 64 patients, to determine percent body fat. RESULTS: Relative weight at the last visit was significantly lower when compared with initial relative weight for the whole sample. Significantly better outcome of relative weight was obtained when six or more visits occurred for the whole sample, and for girls when the days' interval between visits was shorter than 52 d. Variables such as percent body fat, body shape at the first visit, family obesity pattern, length of obesity and pubertal stage, did not significantly influence the outcome of relative weight for the subjects during the treatment. CONCLUSION: Results obtained indicated that good outcomes can be obtained in a program using nutrition education focused on small modifications of eating habits in order to avoid excess energy intake. The best predictors of weight improvement for children and adolescents participating in the program were the higher frequency of visits and shorter intervals between them.

Adolescent↗

PubMed2006

Intra-abdominal placement of antimicrobial-impregnated mesh is associated with noninfectious fever.

The antimicrobial, silver/chlorhexidine, when impregnated on mesh has been demonstrated to resist mesh infection in in vitro and in vivo models. The clinical, human systemic response to intraperitoneal placement of silver/chlorhexidine-impregnated mesh has not been investigated to date. Between October 2002 and November 2004, all in-patients undergoing laparoscopic ventral hernia repair were retrospectively analyzed. All repairs used expanded polytetraflouroethylene (ePTFE) Dual Mesh (DM) or ePTFE impregnated with silver/chlorhexidine, Dual Mesh Plus (DM+). Patient demographics, hernia characteristics, mesh type, operative details, and hospital course data were collected. Noninfectious fevers were defined as a temperature greater than 100.4 F without an identified source. Standard statistical methods were used. During the 2-year study period, 120 patients underwent laparoscopic ventral hernia repair (DM = 55, DM+ = 65). The two groups were similarly matched in terms of age, body mass index, American Society of Anesthesiologists score, defect size, and mesh size. Postoperative fever without an identified source occurred in 10 (18.2%) patients with DM and in 25 (38.5%) patients using DM+ (P = 0.015). A multivariant analysis revealed that only mesh type and body mass index predicted postoperative fever. All fevers resolved within the first 72 hours in the DM patients; however, 16 per cent of the DM+ group had persistent fevers of unknown origin after 72 hours. Within the DM+ group, patients with postoperative fevers had significantly longer postoperative stays (4.8 days vs 3.0 days; P = 0.009). The use of antimicrobial-impregnated ePTFE mesh with silver/chlorhexidine in laparoscopic ventral hernia repair is associated with noninfectious postoperative fever. In our patients, the evaluation and management of these fevers resulted in a significantly longer hospital stay.

Adult↗

PubMed1996

Landing models for volleyball players: a longitudinal evaluation.

The purpose of the study was to longitudinally evaluate lower extremity landing performance of elite volleyball players. Seven female members of a Division 1 NCAA volleyball team completed three data collection sessions (pre-, post-, off-season) during which they performed block-jumps on a dual force platform system (1000 Hz) while being simultaneously videotaped from the right sagittal view (200 Hz). Selected kinetic and lower extremity kinematic variables were calculated. Three dependent variables representing landing impact were identified: first (F 1) and second (F 2) maximum vertical force and knee joint range of motion (K(ROM)). A non-landing performance measure, jump height was also evaluated. Results of repeated measures univariate ANOVAs identified a significant (p < 0.05) difference for test session for K(ROM) suggesting a kinematic change in landing performance across the season. Multiple regression models to predict landing impact identified 88.1 and 98.3% explained variance for F1 and F2 with no significant K(ROM) model identified. F1 was predicted by ankle joint angular velocity during the jump while F2 was best predicted by jump phase braking impulse. Application of the group prediction equations to individual athletes produced differential results across subjects, suggesting the need to tailor the model to the athlete. The results further suggest training/practice-related kinematic differences and have implications for training and assessment of individuals who perform dynamic landing activities.

Adult↗

PubMed1996

Dual-earner families: the importance of work stress and family stress for psychological well-being.

Scales of work stress and family stress as well as outcome measures of depression and self-esteem were completed by 94 mothers and 48 fathers in dual-earner families. Working mothers and working fathers reported equivalent levels of family stress, work stress, job-family interference, and psychological well-being, although mothers did report a higher level of lack of task sharing. Self-esteem and depression of dual-earner mothers and fathers were affected by both job and family stress. Insignificance within their work role affected both self-esteem and depression. Lack of task sharing significantly predicted depression among dual-earner mothers. Lack of challenge in their work role appeared to be a positive characteristic for dual-earner fathers.

Adult↗

PubMed1999

Farm- and host-level risk factors for papillomatous digital dermatitis in Chilean dairy cattle.

A cross-sectional study was conducted in southern Chile between January and March, 1996, to identify risk factors for papillomatous digital dermatitis (PDD) in lactating dairy and dual-purpose cows. A total of 3,265 cows from 22 farms were examined in the milking parlor for PDD lesions. Additional information was collected from dairies' computerized records and by direct interview of managers. Data were analyzed using logistic and logistic-binomial regression (with dairy as a random-effect term). German Red-Pied (dual-purpose) cows were significantly (P < 0.05) less likely (odds ratio (OR) = 0.3) to have PDD lesions than German Black-Pied and Holstein crossbreds. First-parity cows had the highest odds of PDD, and odds diminished, in a dose-effect manner, as parity increased. Odds of PDD increased with increasing days in lactation. Cows that calved during winter were more likely to have PDD (OR = 1.4) than those calving at any other season. Cows on farms that bought heifers in the past 10 years had a 3-fold increase in the odds of PDD compared to those on farms that never bought heifers. Loose-housed cows had a higher risk of PDD (OR = 7), followed by cows in free stalls or in open corrals (OR = 2.8 and 1.3, respectively), compared to cows on pasture all year. Cows on dairies that used a footbath during 1996 were less likely (OR = 0.3) to have PDD than those in dairies not using one. Parlor type was associated with PDD, but this was likely an effect of parlor design on ease of inspection of cows' feet. A policy of trimming all cows' vs. only lame cows' feet and a policy about buying adult cows did not have significant effects on PDD risk.

Animals↗

PubMed2001

Validity of a telephone-administered 24-hour dietary recall in telephone and non-telephone households in the rural Lower Mississippi Delta region.

OBJECTIVE: To determine if 24-hour dietary recall data are influenced by whether data are collected by telephone or face-to-face interviews in telephone and non-telephone households. DESIGN: Dual sampling frame of telephone and non-telephone households. In telephone households, participants completed a 24-hour dietary recall either by face-to-face interview or telephone interview. In non-telephone households, participants completed a 24-hour dietary recall either by face-to-face interview or by using a cellular telephone provided by a field interviewer. SUBJECTS/SETTING: Four hundred nine participants from the rural Delta region of Arkansas, Louisiana, and Mississippi. MAIN OUTCOME MEASURES: Mean energy and protein intakes. STATISTICAL ANALYSES PERFORMED: Comparison of telephone and non-telephone households, controlling for type of interview, and comparison of telephone and face-to-face interviews in each household type using unpaired t tests and linear regression, adjusting for gender, age, and body mass index. RESULTS: Mean differences between telephone and face-to-face interviews for telephone households were -171 kcal (P = 0.1) and -6.9 g protein (P = 0.2), and for non-telephone households -143 kcal (P = 0.6) and 0.4 g protein (P = 1.0). Mean differences between telephone and non-telephone households for telephone interviews were 0 kcal (P = 1.0) and -0.9 g protein (P = 0.9), and for face-to-face interviews 28 kcal (P = 0.9) and 6.4 g protein (P = 0.5). Findings persisted when adjusted for gender, age, and body mass index. No statistically significant differences were detected for mean energy or protein intake between telephone and face-to-face interviews or between telephone and non-telephone households. APPLICATIONS/CONCLUSIONS: These data provide support that telephone surveys adequately describe energy and protein intakes for a rural, low-income population.

Adolescent↗

PubMed2000

Effects of sex, parental status, and spouse work involvement in dual-career couples.

This study examined the effects of sex, parental status, and spouse's work involvement on measures of work-family experiences. Data were collected from women and men employed in similar jobs at the same organizational level in a large professional services firm using anonymously completed questionnaires. A response rate of 70% was achieved. Spouses of men worked fewer hours per week than the men did; spouses of women worked more hours per week than the women did. The effects of three independent variables (sex, presence of children, hours worked by spouse) were considered simultaneously. Each had independent and significant relationships with a majority of the work-family and work outcome measures. Implications for organizations are drawn to address the increasing priority of balancing work and family commitments in dual-career couples.

Adult↗

PubMed2004

Heterotopic en bloc tracheobronchial transplantation with direct revascularization in pigs.

OBJECTIVE: This article describes the application of a novel aortic tube technique for directly revascularized tracheobronchial transplantation with dual blood supply in pigs. METHODS: Eleven adult Large White pigs underwent heterotopic tracheal transplantation with a dual revascularization technique (inferior thyroid artery and bronchial artery). Seven tracheobronchial grafts were perfused ex vivo, and hemodynamic data were collected. RESULTS: At the last evaluation, 6 pigs had normally epithelialized mucus-producing allografts with correct morphologic conformation and cartilage viability. The histopathologic examination revealed homogeneous tissue regardless of biopsy site (trachea, carina, or bronchi), demonstrating the efficacy of the revascularization procedure. Four animals had early ischemic necrosis develop, 2 from acute rejection and 2 from technical mishap. One additional pig had acute rejection starting on the 14th postoperative day. The CD4(+)/CD8(+) ratio was maintained close to or above 0.8 in the subgroup with rejection and below 0.6 in the animals that were correctly immunosuppressed. Pressure-flow curves in 7 ex vivo tracheobronchial grafts showed a nonsignificant difference (P <.12) in vascular resistance between the bronchial artery territory (lower resistance) and the inferior thyroid artery territory. CONCLUSIONS: For the first time, a transplantation technique encompassing the entire trachea, carina, and stem bronchi has been made possible. By means of the dual inferior thyroid and bronchial artery axis, we were able to obtain a structurally healthy and functional graft to replace the main airway.

Animals↗

PubMed2002

Bone loss in patients with rheumatoid arthritis: results from a population-based cohort of 366 patients followed up for two years.

OBJECTIVE: To evaluate the extent of and risk factors for bone loss in a population-based cohort of patients with rheumatoid arthritis (RA) receiving conventional health care. METHODS: In a longitudinal study, clinical data were collected and bone mineral density (BMD) measurements were performed at baseline and after 2 years. Dual-energy x-ray absorptiometry was used for hip and spine BMD measurements. At baseline, patients received advice about lifestyle adjustments and calcium and vitamin D supplementation; during the followup period they were treated with antirheumatic and bone-sparing drugs, according to clinical judgment. RESULTS: After a mean +/- SD of 2.2 +/- 0.2 years, 366 (298 women, 68 men) of the 488 patients who were examined at baseline were reexamined. At that time, 47.9% were current users of corticosteroids and 37.0% were using antiresorptive drugs (hormone replacement therapy, bisphosphonates, or calcitonin). The mean BMD reduction was -0.64% in the femoral neck, -0.77% in the total hip, and -0.29% in the spine at L2-4. BMD was increased at all measurement sites in current users of antiresorptive drugs (0.16-1.64%) but was decreased in patients using calcium and vitamin D alone (-1.99% to -1.39%) and in patients not using any osteoporosis treatment (-1.20% to -0.43%). Current use of corticosteroids was independently associated with increased risk for BMD loss in the total hip (odds ratio [OR] 2.63, 95% confidence interval [95% CI] 1.38-5.00) and spine at L2-4 (OR 2.70, 95% CI 1.30-5.63), whereas current use of antiresorptive drugs was associated with decreased risk for bone loss in the total hip (OR 0.43, 95% CI 0.20-0.89). CONCLUSION: Results of this population-based, 2-year followup study indicate that adequate management of patients with RA, addressing both the rheumatic disease and osteoporosis, protects against bone loss.

Absorptiometry, Photon↗

PubMed1994

The effect of tetrahydrobiopterin on the in situ phosphorylation of tyrosine hydroxylase in rat striatal synaptosomes.

Tetrahydrobiopterin (BH4), the obligatory cofactor of the aromatic amino acid hydroxylases, decreased the in situ 32P-phosphorylation of tyrosine hydroxylase (TH) in rat striatal synaptosomes. Incubation of pre-32P-labeled synaptosomes with BH4 in the presence of a permeant analogue of cAMP decreased the cAMP-stimulated level of 32P label incorporation into TH by about 50%, as determined by immunoprecipitation and autoradiography of SDS-polyacrylamide gels. The extent of inhibition mirrored changes in intrasynaptosomal BH4 levels and varied both as a function of BH4 concentration and length of incubation. A similar decrease in the amount of TH 32P-labeling was observed with the precursor of BH4, sepiapterin. This effect, in turn, was reversed by the inhibitor of sepiapterin reductase, N-acetyl-serotonin. Finally, exposure of pre-32P-labeled synaptosomes to the inhibitor of protein phosphatase 2A, okadaic acid, blocked the response to BH4. Collectively, the data suggest that BH4 stimulates the dephosphorylation of TH in situ and thus may play a dual role both as a cofactor for catalysis and a regulator of hydroxylase activity.

Animals↗