Self-deception as a positive feedback mechanism.

Describes self-deception (SD) as an adaptive strategy based on the definition of SD as a positive feedback mechanism that prevents people from recognizing the contradictions between their sets of behavior and their sets of beliefs. It is argued that SD isolates human systems from moderating influences while intensifying internal forces to excess and that while SD may have been an adaptive strategy in the past, it is a dangerous strategy given the present technologically imbalanced cultures. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The myopic intraocular lens in a phakic eye. Initial experience

The very first experiences with implantation of 3 phakic anterior chamber lenses for high myopia correction are presented. After average 4 month follow up good stability and transparation of concave lenses type ZB5M were observed with accurately achieved correction postoperatively.     

The effects of choroidal or ciliary nerve transection on myopic eye growth induced by goggles

PURPOSE: To determine the role of the choroidal and ciliary nerves and the functions they control, choroidal blood flow (CBF) and accommodation-pupil diameter, respectively, in myopia induced by form-vision deprivation. METHODS: Three groups of chicks were studied: chicks with choroidal nerves cut in the right eye, chicks with ciliary nerves cut in the right eye, and sham control chicks that received the same surgical preparation but no nerve cuts. A plastic, dome-shaped goggle was glued over the right eye of birds in all three groups after orbital surgery, and, 2 weeks later, CBF was measured using laser Doppler flowmetry. Refractive status was then measured using streak retinoscopy, and axial, nasotemporal, and dorsoventral lengths were measured using vernier calipers after enucleation. The eyes were also weighed. RESULTS: In the sham control birds, considerable ocular enlargement in all dimensions and a high degree of myopia (-14.68 diopters) was observed in the goggled eye, and CBF in the goggled eye was 66% of that in the nongoggled eye. In birds with choroidal nerve cuts, the degree of enlargement of the goggled eye was less in all dimensions, and the myopia in the goggled eye (-4.74 D) was attenuated compared to that observed in the sham controls. CBF in the goggled eye was 21% of that in nongoggled eye. Finally, in the birds with ciliary nerve cuts, nasotemporal and dorsoventral enlargement of the goggled eye were similar to that in the shams, but the axial elongation and the degree of myopia (-9.57 D) were less than observed in sham control eyes. As in the shams, CBF in the goggled eye was reduced to 59% of that in the nongoggled eye. CONCLUSIONS: These results show that although elimination of accommodation and severe reductions in CBF do affect eye growth (the latter more so), they do not prevent form-vision deprivation-induced myopia. Thus, either the mechanism of visual deprivation-induced myopia is different from that in idiopathic human myopia, or CBF levels and accommodation do not play a major role in either.     

Transforming growth factor beta as a virulence mechanism for Leishmania braziliensis

Transforming growth factor beta (TGF-beta) has potent down-regulating effects on macrophages and is thus capable of influencing the fate of intramacrophage parasites, including leishmanias. We report the development of a mouse model for the study of the human pathogen Leishmania braziliensis and demonstrate, both in vitro and in vivo, a key regulatory role for TGF-beta in the pathogenesis of infection with this parasite. Recombinant TGF-beta added to cultures of murine peritoneal macrophages led to increased intracellular L. braziliensis replication, whereas addition of neutralizing anti-TGF-beta monoclonal antibody decreased levels of infection. Macrophages infected with L. braziliensis produced biologically active TGF-beta, with a direct correlation between amounts of TGF-beta induced by two parasite isolates and their relative virulence. In vivo, treatment with recombinant TGF-beta rendered avirulent parasites virulent and activated latent L. braziliensis infection. Activation of parasite replication was observed in mice which had been infected with L. braziliensis 15 weeks previously but had not developed lesions or had healed lesions, depending on the parasite isolate used to infect the mice. The exacerbation of L. braziliensis infection in vivo was associated with an increase of interleukin 10 mRNA in the draining lymph node. These results demonstrate that TGF-beta is able to alter the course of in vitro and in vivo infections with L. braziliensis, the latter being characterized by an increase in interleukin 10, an important Th2 helper-T-cell cytokine.     

Being controlled by normative influences: Self-determination as a moderator of a normative feedback alcohol intervention.

The objectives of this research were to evaluate the efficacy of computer-delivered personalized normative feedback among heavy drinking college students and to evaluate controlled orientation as a moderator of intervention efficacy. Participants (N = 217) included primarily freshman and sophomore, heavy drinking students who were randomly assigned to receive or not to receive personalized normative feedback immediately following baseline assessment. Perceived norms, number of drinks per week, and alcohol-related problems were the main outcome measures. Controlled orientation was specified as a moderator. At 2-month follow-up, students who received normative feedback reported drinking fewer drinks per week than did students who did not receive feedback, and this reduction was mediated by changes in perceived norms. The intervention also reduced alcohol-related negative consequences among students who were higher in controlled orientation. These results provide further support for computer-delivered personalized normative feedback as an empirically supported brief intervention for heavy drinking college students, and they enhance the understanding of why and for whom normative feedback is effective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Repair of a complex retinal detachment with proliferative vitreoretinopathy in an eye with extreme scleral thinning

Two new withanolides (steroidal lactones) named coagulin F [27-hydroxy-14,20-epoxy-1-oxo-(22R)-witha-3,5,24-trienolide] (1) and coagulin G [17beta,27-dihydroxy-14,20-epoxy-1-oxo-(22R)-witha-2,5, 24-trienolide] (2) were isolated from the whole plant of Withania coagulans, and their structures were deduced by spectral analysis.     

Electromyograph feedback as a relaxation technique.

Compared an EMG feedback group of 10 normal undergraduate males with 2 control conditions of 10 Ss each. One control group was told to relax but given no specific instructions nor feedback, only a constant tone. The 2nd control group was given instructions about relaxation, a constant tone but no feedback. The feedback group received variable-tone feedback from the frontalis muscle. Every S had 1 baseline session and 7 21-min practice sessions over a 2-wk period. The feedback group achieved significantly lower EMG scores than the 2 control groups, which did not significantly differ between themselves. Measures of subjective anxiety (Mattsson's Anxiety Scale) showed significant decreases between the beginning and end of each session for all 3 groups, but only 1 of the 6 measures of state anxiety (e.g., Taylor Manifest Anxiety Scale, Nowlis Mood Adjective Check List, and Mooney Problem Checklist) favored the feedback group over the controls. No differences between groups emerged on measures of trait anxiety. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autocrine hepatocyte growth factor provides a local mechanism for promoting axonal growth

In this report, we describe a novel local mechanism necessary for optimal axonal growth that involves hepatocyte growth factor (HGF). Sympathetic neurons of the superior cervical ganglion coexpress bioactive HGF and its receptor, the Met tyrosine kinase, both in vivo and in vitro. Exogenous HGF selectively promotes the growth but not survival of cultured sympathetic neurons; the magnitude of this growth effect is similar to that observed with exogenous NGF. Conversely, HGF antibodies that inhibit endogenous HGF decrease sympathetic neuron growth but have no effect on survival. This autocrine HGF is required locally by sympathetic axons for optimal growth, as demonstrated using compartmented cultures. Thus, autocrine HGF provides a local, intrinsic mechanism for promoting neuronal growth without affecting survival, a role that may be essential during developmental axogenesis or after neuronal injury.     

The adaptational system as a dynamical feedback system

Growth hormone receptor is a cytokine-type receptor which is required for normal somatic growth and for numerous metabolic processes. Its complementary DNA (cDNA) has been isolated in various species leading to intensive studies to elucidate the mechanism of action of the growth hormone. However, serious difficulties have been reported in cloning in Escherichia coli, an intact full-length human cDNA. In this study, the cDNA is shown to contain a cryptic bacterial promoter driving inappropriate expression of a part of human growth hormone (hGH) receptor which is toxic for E. coli growth. Identification of this promoter and its inactivation by changing only one nucleotide led us to obtain stable bacterial clones containing a high copy number of full-length coding sequences. This molecular clone was used in a baculovirus/insect cell system to produce large amounts of glycosylated recombinant receptor. Binding studies with 125I-labelled hGH revealed an affinity constant of 2.8 x 10(9) M(-1), similar to that reported for the native liver receptor. This report described a general method of cloning which could be applied to similar unclonable cDNA fragments.     

A clinical experience with a hierarchically controlled myoelectric hand prosthesis with vibro-tactile feedback

The decline of plasma fibronectin after surgery, trauma, and burn, as well as during severe sepsis after injury, appears to limit hepatic Kupffer cell phagocytic activity. Intravenous infusion of gelatin-coated particles to simulate blood-borne particulate collagenous tissue debris in the circulation after injury also depletes plasma fibronectin. We used soluble gelatin conjugated with 125I-labeled dilactitol tyramine (DLT-gelatin) as a model of soluble collagenous tissue debris. We studied its blood clearance as well as organ localization in normal and postburn rats. Fibronectin-deficient plasma harvested early after burn exhibited limited ability to support in vitro phagocytic uptake of the gelatinized microparticles by Kupffer cells in liver tissue from normal rats. However, Kupffer cells in liver tissue from normal and postburn rats phagocytized the test particles at a normal rate when incubated in normal plasma. The DLT-gelatin ligand bound to fibronectin in a dose-dependent manner as verified by its capture with anti-fibronectin coated plastic wells when coincubated with purified fibronectin. By gel filtration chromatography, the binding of fibronectin with the DLT-gelatin ligand was readily detected, resulting in the formation of a high-molecular-weight complex. In normal animals the plasma clearance and liver localization of 125I-DLT-gelatin was competitively inhibited by infusion of excess nonradioactive gelatin. The blood clearance and liver localization of the soluble gelatin ligand were also impaired after burn injury during periods of fibronectin deficiency similarly to the pattern observed with gelatin-coated microparticles. By autoradiography, the cellular site for the uptake of the 125I-DLT-gelatin was primarily but not exclusively hepatic Kupffer cells; 125I-DLT-asialofetuin and 125I-DLT-ovalbumin were removed by hepatocytes and sinusoidal endothelial cells, respectively. Thus, gelatin conjugated with 125I-DLT can be used to simulate blood-borne soluble collagenous tissue debris after burn. It rapidly binds to plasma fibronectin before its hepatic Kupffer cell removal, and its blood clearance is markedly delayed after burn injury during periods of plasma fibronectin deficiency.     

Resource competition as a mechanism for B cell homeostasis

Cellular competition for survival signals offers a cogent and appealing mechanism for the maintenance of cellular homeostasis [Raff, M. C. (1992) Nature (London) 356, 397-400]. We present a theoretical and experimental investigation of the role of competition for resources in the regulation of peripheral B cell numbers. We use formal ecological competition theory, mathematical models of interspecific competition, and competitive repopulation experiments to show that B cells must compete to persist in the periphery and that antigen forms a part of the resources over which B cells compete.     

Effect of retinol palmitate as a treatment for dry eye: a cytological evaluation

OBJECTIVE: To investigate a method of detecting adhesion molecule (CD44) contents in ovarian tumors and its clinical significance. METHODS: In 106 patients with ovarian tumors (50 benign and 56 malignant), the adhesion molecule (CD44) contents in peripheral blood lymphocytes (PBL) and in neoplastic tissues were analysed (quantitatively by using flow cytometric-immunological method). RESULT: (1) The CD44 contents in the PBL of the patients with malignant tumor were obviously higher than those of patients with benign tumors (P<0.05) and than those of the control (P < 0.01); (2) Within the group of patients with malignant tumors, the CD44 contents in the neoplastic tissues were higher than those in the PBL (0.01 < P < 0.05); There was no significant difference in CD44 contents among the different histopathological types, whether benign or malignant; (4) The CD44 contents in the PBL decreased gradually after surgery. CONCLUSION: To analyse the CD44 contents in PBL and neoplastic tissues by flow cytometry may be an important method or parameter to differentiate benign ovarian tumors from malignant tumors and to discover recurrence of metastasis of malignant tumors in early stage.     

Pneumatic retinopexy as supplemental therapy for persistent retinal detachment after scleral buckling operation

BACKGROUND: Factors associated with the development of basal cell carcinomas (BCCs) are radiation exposure, sunlight, trauma, and burns. OBJECTIVE: We wish to further document the relationship between the development of BCCs and previous diathermic exposure for therapeutical purposes. Moreover, we compared the histological subtypes of BCCs developed in patients with or without previous therapy. METHODS: A retrospective study of 1053 patients with BCCs seen at our dermatologic clinic was performed. RESULTS: Twenty-three patients had histories of diathermic therapy for different osteoarticular problems. The interval of time between the treatments and the appearance of the tumor was 12-31 years. The histologic subtypes involved were the same of other BCCs on the same areas. CONCLUSIONS: Our study supports the association of BCCs and diathermic therapy in the development of the tumor of the previously treated areas. Histological subtypes do not seem to be affected by environmental factors but are a characteristic of the site location of the tumor.     

Regulation of tumor growth as a 'total mass' in mice: apoptosis as a major mechanism in altering growth rates of single and multiple coexisting tumor nodules

Earlier studies have suggested that a solid tumor behaves, in its general pattern of growth, like a normal integrated organ. In this study, the growth patterns of spherically shaped tumor nodules are re-examined using an accurate tumor volume-measuring procedure, with the aim of investigating the possible role of apoptosis in regulating tumor growth. Observations revealed at least three distinct phases of growth: rapid growth phase I, slower growth phase II and 'stationary' phase III. Transition from one phase to the next was primarily due to an increase in the level of apoptosis and not to a decrease in the cell proliferation rate. The level of apoptosis, at a given phase, was similar in a single nodule and each of the multiple coexisting nodules of the same tumor line. However, temporal shifts in apoptosis levels caused early phase transition in coexisting nodules, such that their total volume was the same as that of a single nodule. It can be concluded that apoptosis appears to be a primary mechanism regulating tumor growth as a 'total mass', irrespective of whether the tumor exists in one or multiple nodules, if derived from the same tumor line.     

Disgust as a disease-avoidance mechanism.

Many researchers have claimed that the emotion of disgust functions to protect us from disease. Although there have been several discussions of this hypothesis, none have yet reviewed the evidence in its entirety. The authors derive 14 hypotheses from a disease-avoidance account and evaluate the evidence for each, drawing upon research on pathogen avoidance in animals and empirical research on disgust. In all but 1 case, the evidence favors a disease-avoidance account. It is suggested that disgust is evoked by objects/people that possess particular types of prepared features that connote disease. Such simple disgusts are directly disease related, are acquired during childhood, and are able to contaminate other objects/people. The complex disgusts, which emerge later in development, may be mediated by several emotions. In these cases, violations of societal norms that may subserve a disease-avoidance function, notably relating to food and sex, act as reminders of simple disgust elicitors and thus generate disgust and motivate compliance. The authors find strong support for a disease-avoidance account and suggest that it offers a way to bridge the divide between concrete and ideational accounts of disgust. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Projection as a defense mechanism.

Reviews the research related to the hypothesized defensive functions of projection (e.g., attributing one's own undesirable traits to others). Contrary to the predictions, it was found that (a) there is no evidence that projection protects persons from the awareness that they possess undesirable traits, (b) the use of projection follows only some of the predicted patterns, (c) there is no evidence that projection results in undesirable traits being reevaluated as more positive, and (d) there is no reliable or strong evidence that projection results in stress reduction. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mood as a moderator of acceptance of interpersonal feedback.

Two studies demonstrated that feedback is likely to be accepted when its affective tone matches an individual's mood state. In Study 1, Ss in an induced positive mood were more likely to change self-ratings in the direction of positive feedback, whereas Ss in an induced negative mood were more likely to change self-ratings in the direction of negative feedback. In Study 2, after a neutral mood induction, nondepressed Ss were more likely to change self-ratings in the direction of positive feedback, whereas depressed Ss were more likely to change self-ratings in the direction of negative feedback. After a positive mood induction, both nondepressed and depressed Ss were more likely to change self-ratings in the direction of positive feedback. These results suggest that motivations for self-enhancement or self-consistency do not generally underlie acceptance of feedback. Instead, a model of accessibility of information in memory is proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)