Dyadic reciprocal associations between self-efficacy and planning predict sedentary behaviour

Objectives

There are two alternative hypotheses regarding bidirectional associations between self-efficacy and planning in predicting health behaviour change: self-efficacy may establish planning (cultivation hypothesis) or planning may enable the formation of self-efficacy (enabling hypothesis). This study investigates the order in which these two social cognitions are linked in adult–adult dyads in the context of sedentary behaviours (SB).

Design

A longitudinal study with 4 measurement points, spanning 8 months.

Methods

A total of 320 dyads (age: 18–90 years) were enrolled. Dyads included a focus person (who received the recommendation to reduce SB and intended to change their SB), and their partners, who were willing to support the focus persons and intended to reduce their own SB as well. Data were collected at Time 1 (T1), Time 2 (1 week later, T2), Time 3 (T3, 2 months after T1) and Time 4 (T4, 8 months after T1). SB was measured with accelerometers at (T1 and T4). Mediation models with individual and dyadic reciprocal effects were tested with path analyses.

Results

Only one indirect effect was found: A higher level of partners' SB reduction-specific self-efficacy at T2 was related to the focus person's more frequent planning to reduce SB at T3, which, in turn, predicted lower SB time among partners at T4.

Conclusions

The findings provide partial support for the cultivation model (self-efficacy prompting planning) and for dyadic reciprocal associations in the context of SB time reduction among adult dyads.     

Management of fibrous histiocytoma of the corneoscleral limbus: Report of a case and review of the literature

Background: Fibrous histiocytomas of the corneoscleral limbus are rare tumors. We present an additional case and review the treatment approaches in the literature. So far, only light and electron microscopic studies have been performed. We used immunohistochemical stains to further characterize the cellular composition. Methods: The excised lesion was routinely fixed and processed for light microscopy and immunohistochemical studies. For comparison, three dermal fibrous histiocytomas were also examined and processed similarly. Results: The corneolimbal tumor was mainly composed of fibroblasts and histiocytes with a large amount of interstitial collagen, arranged in a storiform pattern. Immunohistochemical stains were positive for histiocytes, fibroblasts, and a marker for mesenchymal cells. The staining pattern of the dermal lesions was similar. Conclusion: Fibrous histiocytomas of the corneolimbal region are morphologically benign, slowly growing and infiltrative tumors. Complete resection, especially of the deep margin, is suggested. The immunohistochemical staining pattern is similar to that of dermal fibrous histiocytomas, which behave in a benign manner.     

Immunohistochemical detection of p140trkA and p75LNGFR neurotrophin receptors in neuroblastoma

In neuroblastoma, high levels of mRNA for p14h ^trkA and p75 ^LNGFR neurotrophin receptors are predictive of favorable outcome. Their evaluation by Northern blot, however, requires substantial amounts of tissue and this prevents their routine evaluation as well as the possibility for multicenter studies to be easily carried out. In an attempt to overcome these limitations, the feasibility and reliability of determining both neurotrophin receptors on cryostat sections by immunohistochemistry were assessed, and these findings were compared to those obtained from Northern blot analysis. Primary tumor samples from 28 untreated patients at all stages were evaluated by using H10 anti-p140 ^trkA and ME20.4 anti-p75 ^LNGFR mAbs. Although weak, positiveimmunostaining was found in 9 of 28 tumors for p140 ^trkA and in 5 of 28 tumors for p75 ^LNGFR . As compared to Northern blot, the concordance rate was 79% (22 of 28 cases) for p140 ^trkA (p < 0.05) and 71% (20 of 28 cases) for p75 ^LNGFR (p < 0.05). No case negative for Northern blot was found to be positive with immunohistochemistry. Since only high mRNA levels for both receptors have been shown to be clinically relevant, their immunohistochemical detection, although less sensitive than Northern blot, can be just as sufficient and reliable as a prognostic tool, and possibly with a better cost-benefit ratio.     

Molecular approach to the nucleo-melanosomal interaction in human melanoma cells

This paper presents evidence that L-tyrosine oxidation products and 5,6-dihydroxyindole, an intermediate of melanin synthesis bind to and modify DNA structure, as tested by extracting cell DNA, using topoisomerase I and denaturation assays. When supercoiled plasmid pCU18 or pBR322 DNAs are treated with 5,6-dihydroxyindole the supercoiled species disappear and are converted to species less mobile in a gel retardation test with respect to relaxed DNA. 5,6-Dihydroxyindole causes an easier acid denaturation of the double helix. The results, that are dose dependent,would point to both intercalation and cross-linking of DNA by 5,6-dihydroxyindole and its oxidation product(s). ³H-L-tyrosine deriving radioactivity, bound to nuclear DNA, is higher at low pH, (5.6) if compared to pH 6.8. The highest radioactivity bound to cell DNA is found during the transition from the amelanotic to the melanotic phenotype in human melanoma cell lines. As a control, the binding of ³H-L-tyrosine radioactivity to human prostate fibroblast DNA was investigated.     

Estrogen increases intracellular p26Bcl-2 to p21Bax ratios and inhibits taxol-induced apoptosis of human breast cancer MCF-7 cells

Recent studies have demonstrated that following estrogen ablation, estrogen responsive breast cancer cells undergo apoptosis. In addition, estrogen receptor (ER) expression has been strongly correlated with the expression of the bcl-2 gene product, p26Bcl-2 protein, which is known to inhibit apoptosis. In the present studies, we investigated whether estrogen affects the intracellular levels of p26Bcl-2 and thereby modulates taxol-induced apoptosis of estrogen responsive human breast cancer MCF-7 cells. Transfer of MCF-7 cells to a culture-medium without estrogens reduced their intracellular p26Bcl-2 levels by 50%. Inclusion of 0.1 M estradiol in the medium produced approximately a four-fold increase in p26Bcl-2, but not p29Bcl-xL or p21Bax levels; the expression of the c-myc and mdr-1 genes remained unchanged. Estradiol-induced four-fold increase in the ratio of the p26Bcl-2 to p21Bax levels caused a significant decline in the lethal, kilobase size DNA fragments of apoptosis, which had resulted when MCF-7 cells were cultured in a medium without estrogen. In addition, in MCF-7 cells, estradiol-induced increase in the intracellular p26Bcl-2 to p21Bax ratios was associated with a significant reduction in the large-sized DNA fragmentation induced by treatment with taxol. The increased ratios also protected MCF-7 cells against taxol-mediated cytotoxicity as assessed by the MTT assay. These results suggest that by modulating p26Bcl-2 levels, estrogens may affect the antitumor activity of taxol and potentially of other anti-breast cancer drugs against estrogen responsive human breast cancer cells.     

Ten-year survival of patients with cancer of the digestive tract in Umbria, Italy

Survival statistics of 4135 incident cases of digestive system cancers in the Umbria region of Italy are reported. The original data are derived from an ad hoc survey carried out in the period 1978--1982. Observed and relative rates at 1, 5 and 10 years are presented separately by sex and age (< 60 and 60 years). In both sexes there are very short survival rates for liver, bile duct and pancreas cancers, whereas about 50% of colon and rectum cancer patients survived at five years. About 20% stomach cancer patients survived at the same time. In males the survival rate for oesophagus cancer is close to 10%. The rates at ten years confirm the trend. Comparisons between sexes show that there is no significant differences in age at first diagnosis. Survival values are higher in females only for rectum cancers. In both sexes, for stomach, colon and rectum sites younger patients had a significantly longer survival than older ones.     

Characterization of the Ca2+ responses evoked by ATP and other nucleotides in mammalian brain astrocytes

1. This study was aimed at characterizing ATP-induced rises in cytosolic free calcium ion, [Ca²⁺]_i, in a population of rat striatal astrocytes loaded with the fluorescent Ca²⁺ probe Fura2, by means of fluorescence spectrometry.
2. ATP triggered a fast and transient elevation of [Ca²⁺]_i in a concentration-dependent manner. The responses of the purine analogues 2-methylthio-ATP (2-meSATP), adenosine-5′-O-(2-thiodiphosphate) (ADPβS), as well as uridine-5′-triphosphate (UTP) resembled that of ATP, while α,β-methylene-ATP (α,β-meATP) and β,γ-methylene-ATP (β,γ-meATP) were totally ineffective.
3. Suramin (50 μM) had only a minor effect on the ATP response, whereas pyridoxal phosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS) (5 μM) significantly depressed the maximum response.
4. Extracellular Ca²⁺ did not contribute to the observed [Ca²⁺]_i rise: removing calcium from the extracellular medium (with 1 mM EGTA) or blocking its influx by means of either Ni²⁺ (1 mM) or Mn²⁺ (1 mM) did not modify the nucleotide responses.
5. Furthermore, after preincubation with 10 μM thapsigargin, the nucleotide-evoked [Ca²⁺]_i increments were completely abolished. In contrast, 10 mM caffeine did not affect the responses, suggesting that thapsigargin-, but not caffeine/ryanodine-sensitive stores are involved.
6. Both application of the G-protein blocker guanosine-5′-O-(2-thiodiphosphate) (GDPβS) (1 mM) and preincubation with pertussis toxin (PTx) (350 ng ml⁻¹) partially inhibited the nucleotide-mediated responses. Moreover, the phospholipase C (PLC) inhibitor U-73122, but not its inactive stereoisomer U-73343 (5 μM), significantly reduced the ATP-evoked [Ca²⁺]_i rise.
7. In conclusion, our results suggest that, in rat striatal astrocytes, ATP-elicited elevation of [Ca²⁺]_i is due solely to release from intracellular stores and is mediated by a G-protein-linked P2Y receptor, partially sensitive to PTx and coupled to PLC.

     

Prevention by morphine of apomorphine- and oxytocin-induced penile erection and yawning: involvement of nitric oxide

The possible involvement of nitric oxide in the prevention by morphine of apomorphine- and oxytocin-induced penile erection and yawning was investigated by measuring the concentration of NO₂- and NO₃- in the dialysate obtained with a vertical microdialysis probe implanted in the paraventricular nucleus of the hypothalamus of male rats. Either apomorphine (80 μg/kgs.c.) or oxytocin (30 ng i.c.v.) increased significantly basal NO₂- and NO₃- concentration in the paraventricular dialysate, penile erection and yawning. Morphine (1, 5 and 10mg/kg i.p.) prevented dose-dependently either apomorphine or oxytocin responses when given 15min before apomorphine or oxytocin. Prevention by morphine of apomorphine and oxytocin responses was abolished by naloxone (3mg/kg i.p.) given 15min before morphine. Morphine prevented apomorphine and oxytocin responses also when given in the lateral ventricles or directly in the paraventricular nucleus. In contrast, the selective agonist of the kappa opioid receptor subtype U-69,593 was found to be ineffective. The present results confirm previous findings showing that morphine acts through μ receptors in the paraventricular nucleus to prevent apomorphine and oxytocin-induced penile erection and yawning and suggest that this morphine effect is mediated by a decreased activity of nitric oxide in the paraventricular nucleus of the hypothalamus. Received: 30 September 1996 / Accepted: 24 January 1997     

Factors Influencing the Growth in Knowledge of Trainees in General Practice

Objectives: The relation between the content of postgraduate training for general practice and the outcome in terms of the growth in knowledge of trainees was investigated. The training variables included were: (1) the number of patients seen per day, (2) the trainer, (3) the practice and (4) the theoretical curriculum.Methods: Subjects were 58 trainee-trainer pairs. Growth in knowledge was assessed by two written tests administered with eight months interval. Training variables were evaluated by means of questionnaires and logbook-registration. The correlation was explored between each of the training variables and the knowledge tests scores. To correct for interactional effects, a step-wise multiple regression analysis was performed with the second test as dependent variable and the first test as well as the training variables as independent variables.Results: Significant growth in knowledge was demonstrated. Non of all training variables investigated explained the variance in scores on the second test equally good or better than the scores on the entry test.Conclusions: The impact of the separate training-components on the growth in knowledge, remains unclear. We may speculate, that the sort of knowledge assessed with the written literature based true/false test is different from the sort of knowledge transferred during every day training: evidence based knowledge versus experience based knowledge. Equally valid is the conclusion that these findings fit into the theory that in adult learning the outcome is more learner than teacher dependent.This revised version was published online in September 2005 with corrections to the Cover Date.     

Formation of extra digits in the interdigital spaces of the chick leg bud is not preceded by changes in the expression of the Msx and Hoxd genes

By in situ hybridization we studied the expression patterns of Msx and Hoxd genes during the late development of the chick leg autopodium (foot) and compared them to patterns during the experimental development of interdigital extra digits. Extra digits are induced in the third interdigital space after various experimental manipulations, such as transient isolation of the interdigit, or removal of the interdigital marginal ectoderm and mesoderm. Msx1 and Msx2 are normally expressed in the interdigital tissue programmed to die. Our experiment changes the fate of the interdigital tissue from cell death to chondrogenesis and provides a good model for studying Msx involvement in defining areas of programmed cell death. Among the proposed roles for Hoxd genes is their involvement in the specification of digit identity early in development. The induction of extra digits allows us to examine whether this new morphogenetic commitment of the interdigital tissue involves changes in the domains of expression of Hoxd genes. Our results show that extra digits develop without a previous modification of the normal pattern of expression of Msx or Hoxd genes. This observation does not support the correlation between the expression of Msx genes and programmed cell death and suggests a role for these genes in maintaining the interdigital tissue in an undifferentiated state. Our results show that an increased number of digits can be formed without modifications in the pattern of expression of the 5-located Hoxd genes and suggest the existence of latent or residual digit organization mechanisms past the time when digits are normally determined, independent of Hoxd gene expression.