Cognitive determinants of energy balance-related behaviours: measurement issues

The burden of disease as a result of overweight and obesity calls for in-depth examination of the main causes of behavioural actions responsible for weight gain. Since weight gain is the result of a positive energy balance, these behavioural actions are referred to as 'energy balance-related behaviours' (EBRBs). In the broadest sense, there are only two EBRBs: food intake and physical activity. However, both diet and physical activity are complex behavioural categories that involve a variety of actions. This article discusses the potential problems and opportunities related to the assessment of cognitive determinants of energy intake and energy expenditure behaviours. We argue for the necessity of studying determinants of EBRBs within an energy balance approach, i.e. focusing on energy input as well as output, instead of only studying dietary change or physical activity behaviour. As a result, however, theoretically sound questionnaires assessing determinants of EBRBs are likely to annoy respondents. It is especially the measurement of the behaviours and the use of belief-based constructs that cause questionnaires to be long, which may lead to low response rates and invalid data. In this article, we propose a careful and systematic consideration of the inclusion or exclusion of measures of cognitive determinants. First, if studies show that an EBRB is strongly influenced by environmental factors and is not or only to a minor extent under intentional control, measurement of cognitions is of little use. Second, only when we have proof that attitudes, norms and perceived behavioural control predict intentions, should we aim to assess the underlying beliefs. Third, since assessment of beliefs results in similar or better prediction than using belief-valuation combinations, we should not 'annoy' respondents with valuation items. Finally, we argue that the traditional paper-and-pencil survey is still the most reliable and practical data collection method. However, pilot studies applying computerised adaptive methods to determinants of EBRBs are encouraged.     

CT of hemangiomas of the upper airways in children

OBJECTIVE: Hemangiomas of the airways in infants are commonly diagnosed at bronchoscopy performed for the investigation of stridor or other respiratory symptoms. Occasionally on bronchoscopy the appearances are atypical or the entire extent of the suspected hemangioma cannot be appreciated. We report on the clinical usefulness of dynamic contrast-enhanced CT in the evaluation of suspected hemangiomas of the airways in infants. CT findings of 11 infants who underwent investigation for a suspected airway hemangioma were correlated with bronchoscopic findings. CONCLUSION: Dynamic contrast-enhanced CT is a valuable noninvasive method for the evaluation of airway hemangiomas. Although it can be used to confirm the diagnosis in patients with equivocal findings on bronchoscopy, we believe that CT findings are specific enough that CT can be recommended as the primary method of establishing the diagnosis. Multiplanar reconstructions illustrate the location, extent, and degree of luminal narrowing and any involvement of adjacent tissues.     

Prominent vascular remnants in the calcaneus simulating a lesion on MRI of the ankle: findings in 67 patients with cadaveric correlation

OBJECTIVE: Our objective was to prove through cadaveric correlation that a frequently seen focus of MRI signal in the calcaneus is benign. CONCLUSION: A characteristic focus of signal (increased T2, decreased T1) in the calcaneus near the attachment of the cervical and interosseous ligaments is a common, benign finding frequently seen on MRI of the foot and ankle.     

Impaired cytoskeletal organization and membrane integrity in lens fibers of a Rho GTPase functional knockout transgenic mouse

To investigate the effects of Rho GTPase inactivation on lens fiber cell cytoskeletal and morphological integrity, a transgenic mouse model expressing C3-exoenzyme (a bacterial toxin) in a lens-specific manner was utilized. Cryosections of whole eyes from C3 transgenic mice and littermate controls were stained for F-actin with rhodamine-phalloidin or immunostained for beta-catenin, aquaporin-0 or connexin-50, and confocal images were recorded. Lens fiber cell morphology was examined at both light and electron microscopic levels. To investigate the influence of Rho GTPase inactivation on the profiles of gene expression, cDNA libraries generated from transgenic and littermate control mouse lenses were screened by cDNA microarray analysis. In contrast to the wild-type lens, fiber cells of the transgenic lens were grossly swollen and disorganized, with abnormal membrane architecture. Staining of F-actin, beta-catenin, aquaporin-0 and connexin-50 was reduced dramatically in the C3 transgenic lens as compared to controls. Western blot analysis and cDNA microarray analysis did not reveal any noticeable decreases in actin, beta-catenin and aquaporin-0 protein levels or expression in C3 transgenic lenses, indicating that altered cytoskeletal organization in response to Rho GTPase inactivation might underlie the noted changes in staining for these proteins. Additionally, cDNA microarray analysis of C3 lens revealed altered expression (at least two-fold, compared to littermate controls) of 44 genes. These include genes encoding extracellular matrix and basement membrane proteins, cell survival and apoptotic pathways, and ion and protein transport. These data indicate that disruption of Rho GTPase function in the developing mouse lens results in abnormal cytoskeletal organization, fiber cell interactions, impaired lens fiber cell morphology and altered gene expression of cellular proteins involved in diverse functions. This work reveals that the morphological and cytoskeletal abnormalities triggered upon Rho GTPase inactivation in lens could be one of the important insults associated with cataract formation in C3 transgenic mouse lens.     

The importance of gut motility in the metabolic control of propionic acidemia

We hypothesized that gut motility likely plays a critical role in the metabolic stability in propionic acidemia (PA). Therefore, 4 known patients with PA (aged 47 months to 185 months) were prospectively studied over 7 days in the Clinical Research Center at Children's Hospital, Boston. Determinations of ammonia, bicarbonate, and amino acids in blood; organic acids and propionylglycine in urine; and a lactulose breath test were conducted under two study conditions: on regular therapy (for 4 days) and on regular therapy plus Senekot (Purdue Frederick Company, Norwalk, Conn), an intestinal motility agent (for 3 days). The total gastrointestinal transit time was calculated using 20 nonabsorbable, inert, radio-opaque markers. The addition of an intestinal motility agent resulted in a significant decrease in blood ammonia, urinary excretion of propionylglycine, and a rise in the ratio of free to total carnitine over baseline. We concluded that enhancement of gut motility can improve metabolic stability in patients with PA.     

Radiographic parameters as prognostic indicators for healing of class II furcation defects

OBJECTIVE: To evaluate radiographic measurements for use as prognostic indicators for healing of class II furcation defects following regenerative therapy. MATERIAL AND METHODS: In 17 patients (eight females), 33 class II furcation defects (mandibular buccal (n=10) and lingual (n=12), and maxillary buccal (n=11)) were treated using the barrier membrane technique. Twenty-six furcations were treated using a bioabsorbable membrane, while a nonresorbable membrane was used to treat the remaining seven furcation defects. Clinical parameters and standardized radiographs were obtained before as well as 6 and 24 months after therapy. All radiographs were digitized and evaluated by an examiner blinded to the clinical data. The following distances were measured: cemento-enamel junction line (CEJ-line) to alveolar crest (AC) at the furcation site (AC-CEJ line), CEJ-line to the furcation fornix (Fx-CEJ line), width of the furcation at the level of the AC (FW) as well as the distance from Fx to a straight line between the AC mesial and distal of the tooth (Fx-AC line). RESULTS: Statistically significant (p<0.001) horizontal attachment gains could be observed 6 and 24 months after therapy (6 months: 1.49+/-0.85 mm; 24 months: 1.14+/-0.91 mm). However, a small but statistically significant (p=0.031) attachment loss of 0.35 mm was observed between the 6 and 24 months examination. Multilevel regression analyses identified baseline probing depth (p=0.0017) and 3 of the radiographic distances as prognostic factors: Fx-CEJ line (p=0.014), FW (p=0.0535), Fx-AC line (p=0.0827). CONCLUSION: The analysis of presurgical radiographs may yield information on the success of the regenerative therapy of buccal and lingual class II furcation defects. A long root trunk, a wide furcation entrance and an Fx coronal to the AC have negative influences on the success of therapy. Further, a deep probing depth at the furcation site at baseline increases the likelihood for more favourable horizontal attachment gain in furcations.     

Gestational diabetes mellitus--implications of different treatment protocols

OBJECTIVE: To assess the impact of different management approaches to gestational diabetes mellitus (GDM) on perinatal outcome. PATIENTS AND METHODS: The study group consisted of 2,060 patients with GDM treated in our center from January 1980 through December 1999. Four time periods were defined on the basis of changes in treatment protocols. Perinatal complications were compared between the periods and with normal pregnancy controls. RESULTS: The last two periods (1993-1999) were characterized by lower mean glucose level, lower mean gestational age at delivery, and a decline in macrosomia, shoulder dystocia and perinatal mortality rates, but also by high rates of labor induction and Cesarean delivery. A significant difference was found between the GDM and normal control groups in rates of labor induction (38.6% vs 10.8%, p < 0.001) and Cesarean delivery (34% vs 20%, p < 0.001) for the last period. CONCLUSIONS: Perinatal complications are preventable with good glycemic control and early induction of labor, but at a cost of a higher Cesarean section rate.     

Effect of urinary versus recombinant follicle-stimulating hormone on platelet function and other hemostatic variables in controlled ovarian hyperstimulation

OBJECTIVE: To determine the effect of urinary versus recombinant FSH on platelet function and hemostatic variables in women undergoing controlled ovarian hyperstimulation cycles. DESIGN: Randomized clinical study. SETTING: Major university-based infertility and in vitro fertilization unit and hemostasis laboratory. PATIENT(S): Ten healthy women (in vitro study), and 24 women undergoing routine controlled ovarian hyperstimulation cycles (in vivo study), randomly assigned to receive either urinary (u-FSH) or recombinant gonadotropin (r-FSH). INTERVENTION(S): In vitro study: effect of preincubation of plasma with u-FSH or r-FSH, in the presence or absence of estradiol, on platelet function and coagulation parameters. In vivo study: Changes in platelet function and coagulation parameters after treatment with u-FSH or r-FSH during controlled ovarian hyperstimulation cycles. MAIN OUTCOME MEASURE(S): Platelet aggregation and ATP release, activated protein C resistance ratio, free protein S. RESULT(S): In vitro study: Platelet aggregation and ATP release were significantly inhibited by u-FSH relative to r-FSH in both the presence and absence of estradiol (P=.047). In vivo study: Platelet function was significantly inhibited after treatment with u-FSH (P=.05) but not with r-FSH. In both studies, small changes of minor clinical significance were noted in activated protein C resistance and free protein S levels. CONCLUSION(S): The different platelet response to u-FSH and r-FSH may have clinical implications in selected patients, especially those at risk of thromboembolic complications, in decisions regarding the appropriate medication for controlled ovarian hyperstimulation cycles.     

Genetic influence on prolonged gestation: a population-based Danish twin study

OBJECTIVE: The purpose of this study was to test a possible genetic component to prolonged gestation. STUDY DESIGN: The gestational duration of single, first pregnancies by both female and male twins was obtained by linking the Danish Twin Registry, The Danish Civil Registration System, and the Danish Medical Birth Register. A total of 2588 same-sex twin pairs of whom both cotwins became parents during 1978 to 1996 were identified. RESULTS: The concordance rate for female twin pairs for a gestation of > or =41 weeks and > or =42 weeks was higher for monozygotic twin pairs than for dizygotic twin pairs, which indicates genetic effects. Biometric modeling suggested that genetic factors account for 23% to 30% of the liability to prolonged gestation. The difference in concordance rate between monozygotic and dizygotic male twin pairs was small, and the best fitting model indicated no genetic factors. CONCLUSION: Maternal genes influence prolonged gestation. However, a substantial paternal genetic influence through the fetus was not found.