Television, walking, and diet: associations with postpartum weight retention

BACKGROUND: For many women, pregnancy begets long-term weight gain. Modifiable behaviors that contribute to postpartum weight retention have not been well studied. METHODS: Prospective cohort study of 902 women enrolled in Project Viva, examining associations of postpartum television viewing, walking, and trans fat intake with weight retention equal to or greater than 5 kg at 12 months postpartum. Data were collected in 1999-2003 and analyzed in 2005-2006. RESULTS: At 6 months postpartum, women reported a mean (SD) of 1.7 (1.3) hours of television viewing, 0.7 (0.7) hours of walking, and 1.1% (0.5) of energy intake from trans fat per day. At 1 year, participants retained a mean of 0.6 kg (range: -17.3 to 25.5), and 12% retained at least 5 kg. In multivariate logistic regression models, adjusting for maternal sociodemographics, parity, prepregnancy body mass index, gestational weight gain, breastfeeding, and smoking, the odds ratio of retaining at least 5 kg was 1.24 (95% confidence interval [CI]: 1.06-1.46) per daily hour of television viewing, 0.66 (95% CI: 0.46-0.94) per daily hour of walking, and 1.33 (95% CI: 1.09-1.62) per 0.5% increment in daily energy intake from trans fat. Women who watched less than 2 hours of television, walked at least 30 minutes, and consumed trans fat below the median had an odds ratio of 0.23 (95% CI: 0.08-0.66) of retaining at least 5 kg. CONCLUSIONS: Postpartum television viewing, walking, and trans fat intake were associated with weight retention. Interventions to modify these behaviors may help reduce excess postpartum weight gain and prevent obesity among women.     

Antecedents of obesity - analysis, interpretation, and use of longitudinal data

The obesity epidemic causes misery and death. Most epidemiologists accept the hypothesis that characteristics of the early stages of human development have lifelong influences on obesity-related health outcomes. Unfortunately, there is a dearth of data of sufficient scope and individual history to help unravel the associations of prenatal, postnatal, and childhood factors with adult obesity and health outcomes. Here the authors discuss analytic methods, the interpretation of models, and the use to which such rare and valuable data may be put in developing interventions to combat the epidemic. For example, analytic methods such as quantile and multinomial logistic regression can describe the effects on body mass index range rather than just its mean; structural equation models may allow comparison of the contributions of different factors at different periods in the life course. Interpretation of the data and model construction is complex, and it requires careful consideration of the biologic plausibility and statistical interpretation of putative causal factors. The goals of discovering modifiable determinants of obesity during the prenatal, postnatal, and childhood periods must be kept in sight, and analyses should be built to facilitate them. Ultimately, interventions in these factors may help prevent obesity-related adverse health outcomes for future generations.     

STUDIES ON THE PATHOGENESIS OF FEVER : VIII. FURTHER OBSERVATIONS ON THE ROLE OF ENDOGENOUS PYROGEN IN ENDOTOXIN FEVER

Rabbits made granulocytopenic with nitrogen mustard have been shown to generate serum endogenous pyrogen when given a fever-producing dose of bacterial endotoxin. This finding is in accord with the hypothesis that endogenous pyrogen plays a central role in the pathogenesis of endotoxin fever. The fact that leucopenic animals produce less serum-endogenous pyrogen than normal animals given the same dose of endotoxin has also been confirmed and suggests that polymorphonuclear leucocytes constitute a major source of the endogenous pyrogen which is demonstrable in the circulation during endotoxin fever.     

Content Analysis of Motivational Counseling Calls Targeting Obesity-Related Behaviors Among Postpartum Women

Our objective was to examine mothers’ perspectives of obesity-related health behavior recommendations for themselves and their 0–6 month old infants. A health educator conducted 4 motivational counseling calls with 60 mothers of infants during the first 6 months postpartum. Calls addressed 5 behaviors for infants (breastfeeding, introduction of solid foods, sleep, TV, hunger cues), and 4 for mothers (eating, physical activity, sleep, TV). We recorded detailed notes from each call, capturing responsiveness to recommendations and barriers to change. Two independent coders analyzed the notes to identify themes. Mothers in our study were more interested in focusing on their infants’ health behaviors than on their own. While most were receptive to eliminating their infants’ TV exposure, they resisted limiting TV for themselves. There was some resistance to following infant feeding guidelines, and contrary to advice to avoid nursing or rocking babies to sleep, mothers commonly relied on these techniques. Return to work emerged as a barrier to breastfeeding, yet facilitated healthier eating, increased activity, and reduced TV time for mothers. The early postpartum period is a challenging time for mothers to focus on their own health behaviors, but returning to work appears to offer an opportunity for positive changes in this regard. To improve weight-related infant behaviors, interventions should consider mothers’ perceptions of nutrition and physical activity recommendations and barriers to adherence.     

Electronic reminders for cancer prevention: factors associated with preference for automated voice reminders or text messages

Objective

Prompting may promote engagement with behavior change interventions. Prompts can be delivered inexpensively via automated voice response (AVR) reminders or short message service (SMS) text messages. We examined the association between participants' characteristics and preferred reminder modality.

Methods

Healthy Directions 2 is a cluster randomized controlled trial implemented in Boston, Massachusetts to promote change in multiple behavioral cancer risk factors. At baseline (2009), participants completed a survey assessing socio-demographics, health status, height/weight, and factors associated with technology. One-third of participants randomized to receive the intervention (n = 598) were randomized to receive automated reminders, with participants selecting modality.

Results

28% (167/598) of participants selected SMS reminders. Controlling for clustering by primary care provider, younger participants (OR = 0.97, 95% CI = (0.95, 0.99), p < 0.01), those most comfortable with computers (very uncomfortable OR = 0.54, 95% CI = (0.29, 1.01), p ≤ 0.05: referent group = very comfortable), and those who frequently sent/received text messages (never OR = 0.09 CI = (0.04, 0.16) p < 0.01; 1-3 times/month OR = 0.38, 95% CI = (0.15, 0.93) p = 0.04: referent group = 1-5 times/week) were more likely to choose SMS.

Conclusions

Interventions should make both modalities available to ensure that more participants can benefit from prompting. Studies examining the effect of automated reminders may have reduced effectiveness or generalizability if they employ only one modality.     

On the interaction of rabbit antithrombin III with the luminal surface of the normal and deendothelialized rabbit thoracic aorta in vitro

Pure rabbit antithrombin III was isotope labeled (with 125I or 3H) by two different methods; neither procedure caused a loss of antithrombin activity although both methods affected the affinity of the protein for Sepharose-heparin. From segments from freshly excised rabbit aorta, the uptake of isotope-labeled antithrombin III by the endothelium was rapid and saturable, although relatively small compared to the uptake of thrombin; binding of 3H-antithrombin III to the endothelium resembled that of 125I-antithrombin III. Transendothelial passage of antithrombin III into the subendothelial layers (intima-media) was slow and progressive. Endothelium binding was not affected by pretreating the vessel with either heparin, thrombin, or glycosaminoglycan-specific enzymes. Endothelium-bound antithrombin III was not selectively displaced by either heparin or thrombin. In contrast, endothelium-bound thrombin was rapidly dislodged by antithrombin III as a thrombin- antithrombin III complex. The surface of the deendothelialized aorta (ie, subjected to a balloon catheter) bound antithrombin III avidly. Pretreatment of the deendothelialized vessel with glycosaminoglycan- specific enzymes, particularly heparitinase, decreased intima-media binding by up to 80%. 125I-antithrombin III, when bound to the deendothelialized vessel surface, was actively displaced by either heparin, thrombin, or by unlabeled antithrombin III. The relatively poor binding of antithrombin III compared with that of thrombin by the endothelium in vitro supports an earlier proposal (Lollar P, Owen WG: J Clin Invest 66:1222-1230, 1980) that thrombin bound to high-affinity sites, possibly pericellular proteoglycan, of the endothelium is inactivated by plasma antithrombin III in vivo. Such a situation probably holds for large arteries at least.     

Human platelet fibrinogen: purification and hemostatic properties

Conditions were developed in which 80% to 90% of platelet fibrinogen could be routinely purified in nondegraded form from the fluid phase of platelet suspensions stimulated with the calcium ionophore, A23187, in the presence of calcium, leupeptin, and prostaglandin E1. Fibrinogen was separated from other released proteins by chromatography on diethylaminoethanol (DEAE)-cellulose using a continuous pH and ionic strength gradient. Purified platelet fibrinogen, greater than 98% homogeneous by immunoelectrophoresis and sodium-dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE), consisted of intact A alpha, B beta and gamma A chains, but not gamma' chains, and was 95% to 96% clottable. Platelet fibrinogen was shown to compete for the binding of radiolabeled plasma fibrinogen to ADP-activated platelets in a manner identical to that of unlabeled plasma fibrinogen itself. Also, at equivalent protein concentrations, platelet and plasma fibrinogens supported platelet aggregation to an equivalent extent. Based upon these results, we conclude that there is no significant difference between platelet and plasma fibrinogen with respect to their size, their clottability, their affinity for the activated platelet fibrinogen receptor, or their capacity to support subsequent platelet aggregation.     

Delayed activation of quiescent donor hematopoietic stem cells in the host marrow cavity by anti-host monoclonal antibody

To understand the mechanisms controlling hematopoietic engraftment in untreated, normal recipients, we investigated the fate of parental, donor hematopoietic stem cells after apparent graft failures in unconditioned F1 hybrid recipient mice. By administering an anti-host H- 2K monoclonal antibody, which targets host cells but spares the donor, we found that chimerism could be induced by delayed conditioning in animals with apparent graft failure. Engraftment kinetics in the host were followed by typing individual colony forming unit-- granulocyte/macrophage (CFU-GM) colonies for their origin and showed that parental cells, which were otherwise virtually absent, become promptly detectable within the marrow cavity after antibody administration. Marrow transfers to secondary hosts suggested that parental stem cells were present in the marrow of the untreated recipients. These findings establish that the elimination of all parental cells cannot account for the absence of peripheral blood chimerism in the unconditioned F1 hybrid recipient. Thus, viable and functional donor stem cells, which remain quiescent in the host marrow, can be activated by a selective conditioning regimen and can rescue an apparent graft failure. The selective activation in vivo of marked stem cells in an unirradiated microenvironment may be a useful system to study the regulation of cellular proliferation within the marrow cavity.     

The value of flow cytometric analysis of platelet glycoprotein expression of CD34+ cells measured under conditions that prevent P- selectin-mediated binding of platelets

In the present study, we show by adhesion assays and ultrastructural studies that platelets can bind to CD34+ cells from human blood and bone marrow and that this interaction interferes with the accurate detection of endogenously expressed platelet glycoproteins (GPs). The interaction between these cells was found to be reversible, dependent on divalent cations, and mediated by P-selectin. Enzymatic characterization showed the involvement of sialic acid residues, protein(s). The demonstration of mRNA for the P-selectin glycoprotein ligand 1 (PSGL-1) in the CD34+ cells by polymerase chain reaction (PCR) analysis suggests that this molecule is present in these cells. Under conditions that prevent platelet adhesion, a small but distinct subpopulation of CD34+ cells diffusely expressed the platelet GPIIb/IIIa complex. These cells were visualized by immunochemical studies. Furthermore, synthesis of mRNA for GPIIb and GPIIIa by CD34+ cells was shown using PCR analysis. The semiquantitative PCR results show relatively higher amounts of GPIIb mRNA than of PF4 mRNA in CD34+CD41+ cells in comparison with this ratio in platelets. This finding is a strong indication that the PCR results are not caused by contaminating adhering platelets. MoAbs against GPIa GPIb alpha, GPV, P- selectin, and the alpha-chain of the vitronectin receptor did not react with CD34+ cells. The number of CD34+ cells expressing GPIIb/IIIa present in peripheral blood stem cell (PBSC) transplants was determined and was correlated with platelet recovery after intensive chemotherapy in 27 patients. The number of CD34+CD41+ cells correlated significantly better with the time of platelet recovery after PBSC transplantation (r = .83, P = .04) than did the total number of CD34+ cells (r = .55). Statistical analysis produced a threshold value for rapid platelet recovery of 0.34 x 10(6) CD34+CD41+ cells/kg. This study suggests that if performed in the presence of EDTA the flow cytometric measurement of GPIIb/IIIa on CD34+ cells provides the most accurate indication of the platelet reconstitutive capacity of the PBSC transplant.     

Liver transplant recipients: portable duplex US with correlative angiography

Twenty patients, aged 4 months to 58 years, were evaluated for liver transplantation by duplex sonography, and 15 transplantations were completed; 42 postoperative examinations were performed. Sonographic findings were correlated with seven preoperative and five postoperative angiographic evaluations. Preoperative duplex US findings included tumors, portal vein occlusion, varices, biliary obstruction, and variant vascular anatomy. Postoperative findings included hepatic artery occlusion, portal vein occlusions (one with cavernous transformation), portal vein stenosis, biliary obstruction, intrahepatic and extrahepatic fluid collections, and air in the portal vein due to ischemic bowel. Use of angiography allowed confirmation of the vascular abnormalities and demonstrated evidence of rejection in patients with normal Doppler waveforms. Duplex sonography is a valuable portable technique for evaluating these patients and can be used in triage of patients requiring angiography.