Social media does not elicit a physiological stress response as measured by heart rate and salivary cortisol over 20-minute sessions of cell phone use

The pervasive use of social media has raised concerns about its potential detrimental effects on physical and mental health. Others have demonstrated a relationship between social media use and anxiety, depression, and psychosocial stress. In light of these studies, we examined physiological indicators of stress (heart rate to measure autonomic nervous system activation and cortisol to assess activity of the hypothalamic-pituitary-adrenal axis) associated with social media use and investigated possible moderating influences of sex, age, and psychological parameters. We collected physiological data from 59 subjects ranging in age from 13 to 55 across two cell phone treatments: social media use and a pre-selected YouTube playlist. Heart rate was measured using arm-band heart rate monitors before and during cell phone treatments, and saliva was collected for later cortisol analysis (by enzyme immunoassay) before and after each of the two cell phone treatments. To disentangle the effects of cell phone treatment from order of treatment, we used a crossover design in which participants were randomized to treatment order. Our study uncovered a significant period effect suggesting that both heart rate and cortisol decreased over the duration of our experiment, irrespective of the type of cell phone activity or the order of treatments. There was no indication that age, sex, habits of social media use, or psychometric parameters moderated the physiological response to cell phone activities. Our data suggest that 20-minute bouts of social media use or YouTube viewing do not elicit a physiological stress response.

[Conclusions and recommendations of a WHO expert consultation meeting on iron supplementation for infants and young children in malaria endemic areas]

This article presents the results of an expert consultation meeting aimed at evaluating the safety and public health implications of administering supplemental iron to infants and young children in malaria-endemic areas. Participants at this meeting that took place in Lyon, France on June 12-14, 2006 reached consensus on several important issues related to iron supplementation for infants and young children in malaria-endemic areas. The conclusions in this report apply specifically to regions where malaria is endemic.

Fast trains, slow boats, and the ancestry of the Polynesian islanders

The question of the origins of the Polynesians has, for over 200 years, been the subject of adventure science. Since Captain Cook's first speculations on these isolated Pacific islanders, their language affiliations have been seen as an essential clue to the solution. The geographic and numeric centre of gravity of the Austronesian language family is in island Southeast Asia, which was therefore originally seen as their dispersal homeland. However, another view has held sway for 15 years, the 'out of Taiwan' model, popularly known as the 'express train to Polynesia'. This model, based on the combined evidence of archaeology and linguistics, proposes a common origin for all Austronesian-speaking populations, in an expansion of rice agriculturalists from south China/Taiwan beginning around 6,000 years ago. However, it is becoming clear that there is, in fact, little supporting evidence in favour of this view. Alternative models suggest that the ancestors of the Polynesians achieved their maritime skills and horticultural Neolithic somewhere between island Southeast Asia and Melanesia, at an earlier date. Recent advances in human genetics now allow for an independent test of these models, lending support to the latter view rather than the former. Although local gene flow occurring between the bio-geographic regions may have been the means for the dramatic cultural spread out to the Pacific, the immediate genetic substrate for the Polynesian expansion came not from Taiwan, but from east of the Wallace line, probably in Wallacea itself.

Partial trisomy 20p: familial occurrence

Partial trisomy 20p syndrome in an uncle and niece are compared to 32 previous cases.

The prevalence of attentional problems and the effect of methylphenidate in children with myelomenigocele

The prevalence of attentional problems, and the effect of methylphenidate was evaluated in a clinic population of children with myelomeningocele. Families of 79 children between the ages of 6 and 15 years were screened for the presence of attention problems in their children, using Conners' questionnaires for parents and teachers, and/or the DSM-IV checklist. Thirty-nine per cent of the children exhibited attention problems, primarily without hyperactivity. Fourteen children with attentional problems were enrolled in a double-blind placebo-controlled trial methylphenidate. Response to methylphenidate was assessed with Conners' questionnaires, Conners' Continuous Performance Test, and a battery of selected neuropsychological tests. No statistically significant response was measured for the group while on methylphenidate. Four children were clinical responders to methylphenidate. The prevalence of attentional problems in children with myelomeningocele is high, and effective medication therapy needs to be studied further.

The effects of carcinogenic methylcholanthrene on carbohydrate residues of NK cells

The present study examines the effect of methylcholanthrene (MCA), a a carcinogenic polycyclic hydrocarbon, on the carbohydrate receptor determinants (RD) on natural killer (NK) cell surface using the bead-coupled lectin assay. Murine NK cells exhibited different degrees of preferential binding to the specific lectins tested. Of the ten lectins tested, five exhibited a positive binding affinity while the remaining five exhibited no or insignificant binding. NK cells bind to beads derivatized with mannose specific lectins: Concanavalin A (Con A), Lens culinaris, and Pisum sativum. NK cells also bind to other lectin beads such as Triticum vulgaris (GalNac) and Vicia villosa (D-GlcNAc). All these lectin beads exhibited greater than 90% adhesion. The underivatized control beads exhibited no NK binding. The NK cells that were exposed to MCA for 2 h demonstrated a significant decrease in lectin bead-cell coupling in a dose dependent manner. MCA (10 micrograms/mL) caused a 17.8%, 40% and 4.7% decrease in binding affinity when introduced to the mannose specific lectins; Con A, L. culinaris and P. sativum beads, respectively. The binding of T. vulgaris and V. villosa to NK cells was inhibited (23.4% and 28%) by MCA treatment. An increase in the dose to 20 micrograms/mL resulted in a greater inhibition in binding affinity towards lectin beads. Con A, 35.3%, L. culinaris, 62.6%, P. sativum, 30.9%, T. vulgaris, 44.2% and V. villosa, 46.2%. The effect of MCA activation and cytotoxic response. Hydrolysis of PI metabolites (PIP and PIP2) cause generation of secondary messenger: inositol-1,4,5-triphosphate and diacylglycerol, both of which elicit an immune response through their products (Ca2+ and PKC) respectively. Identification of the relationship between receptor level, induction of second messenger and cytotoxic activity may resolve the molecular basis of suppression of NK cytotoxicity by MCA and other PAH compounds.

A novel family of T-box genes in urodele amphibian limb development and regeneration: candidate genes involved in vertebrate forelimb/hindlimb patterning

In certain urodeles, a lost appendage, including hand and foot, can be completely replaced through epimorphic regeneration. The regeneration process involves cellular activities similar to those described for embryogenesis. Working on the assumption that the morphological pattern specific for a forelimb or a hindlimb is controlled by different gene activities in the two limbs, we employed a mRNA differential display screen for the detection of candidate limb identity genes. Using this approach, we have isolated a newt gene which in regenerating and developing limbs reveals properties expected of a gene having a role in controlling limb morphology: (1) it is exclusively expressed in the forelimbs, but not hindlimbs, (2) during embryonic development its expression is co-incident with forelimb bud formation, (3) it has an elevated message level throughout the undifferentiated limb bud and the blastema, respectively, and (4) it is expressed only in mesenchymal, but not in epidermal tissues. This novel newt gene shares a conserved DNA-binding domain, the T-box, with putative transcription factors including the Brachyury (T) gene product. In a following PCR-based screen, we used the evolutionarily conserved T-box motif and amplified a family of related genes in the newt; their different expression patterns in normal and regenerating forelimbs, hindlimbs and tail suggest, in general, an important role of T-domain proteins in vertebrate pattern formation.

Identification of differentially expressed messenger RNAs in human melanocytes and melanoma cells

The phenotype of malignant lesions is a reflection of genetic events altering the RNA and protein expression patterns of normal cells. We have investigated RNA expression patterns distinguishing normal melanocytes (FM 902), a primary melanoma cell line (WM 793), and its variant cell line (1205-LU), selected for metastatic phenotype in athymic mice. Using mRNA differential display, we identified 42 different cDNA PCR products with cell line-specific expression patterns. Direct sequence analysis matched approximately 50% of the cDNA PCR products with gene sequences accessible in DNA databases. Among the known genes, two functionally distinct groups were recognized: (a) genes encoding ribosomal and mitochondrial proteins that were predominantly up-regulated in the malignant cells; and (b) genes encoding modulators of the immune response. Among the immunomodulators, the T-cell antigen MART-1 and the protease inhibitor alpha2-macroglobulin were detected in the melanocyte cell line but not in the tumor cells. By contrast, mRNAs for the complement inhibitor CD59 and the cytokine IL-1beta were found to be overexpressed in the malignant melanoma cells. RNA slot blot hybridization on a larger panel of melanocyte and melanoma cell lines confirmed differential expression of 15 of 42 genes including MART-1, alpha2-macroglobulin, and CD59. This molecular screening approach identified also three partially characterized and three novel sequences with differential expression patterns in normal and malignant melanocytes.

Advanced mRNA differential display: isolation of a new differentially regulated myosin heavy chain-encoding gene in amphibian limb regeneration

In an effort to make mRNA differential display more amenable as a molecular screen, we have optimized the technology for the isotopic and non-isotopic detection of differentially regulated mRNAs. The number of amplification rounds in the displays was significantly reduced, resulting in the semi-quantitative detection of expression patterns of both low- and high-abundance transcripts. Moreover, we extended the method beyond the display of mRNAs by introducing a direct sequencing approach for the fast molecular analysis of isolated cDNAs. Applying this improved technique to the regenerating amphibian limb system, we have identified cDNA PCR products with a temporal difference in expression. This differential regulation was confirmed by Northern analysis, and DNA sequencing uncovered a novel newt differentiation-specific transcript encoding a skeletal myosin heavy chain (MHC).

Supernumerary chromosome marker (1) in a developmentally delayed child

A 15-month-old boy with mild developmental delay and several minor anomalies was found to be mosaic 46,XY/47,XY ,+mar(1). The marker r(1) was a small de novo ring identified by FISH with a painting type DNA probe.

Caring for gravely ill children

BACKGROUND

Much has been written about the care of the hopelessly ill adult, but there is little guidance for pediatric health care professionals in the management of children who are critically or terminally ill.

METHODS

Through a 3-day meeting in Tarrytown, NY, attended by a group of pediatricians and others directly involved in these issues, a principled approach was developed for the treatment of, and health care decision-making for, children who are gravely ill.

RESULTS

The group agreed that the needs and interests of the child must be the central focus of any treatment plan and that the child should be involved to as great extent possible, consistent with developmental maturity, in the decision-making process. Quality of future life should be viewed as being relevant in all decisions. Parents are believed to be the natural guardians of children and ought to have great latitude in making decisions for them. However, parental discretion is not absolute and professionals must maintain an independent obligation to protect the child's interests.

CONCLUSIONS

Decision-making should be collaborative among patient, parents, and professionals. When conflict arises, consultation and ethics committees may assist in resolution. When cure or restoration of function is no longer possible, or reasonable, promotion of comfort becomes the primary goal of management. Optimal use of pain medication and compassionate concern for the physical, psychological, and spiritual well-being of the child and family should be the primary focus of the professionals caring for the dying child.

The anatomy and physiology of cortical mechanisms of cardiac control

For nearly fifty years, attention has repeatedly been drawn to electrocardiographic changes accompanying acute stroke. The mechanism was unknown. These alterations, which are more frequent after hemisphere than brain stem infarction, are not solely due to concomitant myocardial ischemia. Recently, cardiac chronotropic organization has been shown within the posterior rat insular cortex. Stimulation of that site mimics both the electrocardiographic changes and the cardiac pathology accompanying acute stroke. These effects are attended by increased sympathetic activity. In addition, stimulation of the human right insula increases sympathetic cardiovascular tone, whereas parasympathetic increases are more frequent during left insula stimulation. It is suggested that right middle cerebral artery infarction disinhibits insular function, resulting in increased sympathetic cardiovascular tone and the cardiac consequences of stroke.

Evaluation of latex allergy in patients with meningomyelocele

Seventy-six patients with meningomyelocele were evaluated for latex sensitivity by medical history and epicutaneous skin testing. Four different latex glove extracts, two nonlatex glove extracts, cornstarch, selected inhalant antigens, and negative and positive controls were used for skin testing. Forty-nine patients (64.5%) were skin test positive to latex extracts (latex-positive group). Twenty-four patients (49%) of the latex-positive group and none of the latex-negative group had histories of immediate reactions to latex products (P less than .001). The latex-positive group had a higher mean number of surgical procedures, 12.67 +/- 11.27, compared with 6.89 +/- 6.55 (P less than .001) in the latex-negative group. Twenty-three of the latex-positive patients (47%) used latex products daily compared to seven patients (26%) in the latex-negative group (P = .073). Twenty latex-positive patients (41%) had atopy compared with five patients (19%) of the latex negative group (P = .041). There was no significant difference between the two groups in age, sex, daily catheterization, or positive skin tests to cornstarch. All 76 patients tested negative to the nonlatex glove extracts. Ten control subjects tested negative for all latex and nonlatex glove extracts.

The insular cortex and the pathophysiology of stroke-induced cardiac changes

Over the past fifty years considerable clinical evidence has accrued to demonstrate involvement of the cerebral cortex in cardiac function. Hemispheric stroke is often associated with electrocardiographic (ECG) evidence of cardiac repolarisation abnormalities. In addition strokes of all types are associated with specific pathological changes in the ventricular myocardium (myocytolysis). These effects are not attributable to concomitant cardiac ischemic disease in the majority of cases. The insular cortex has recently been shown to contain a site of cardiac representation. Prolonged stimulation of this region in the rat produces ECG and cardiac pathological changes similar to those observed after human stroke. It is suggested that middle cerebral artery stroke in certain cases either directly or indirectly leads to insular disinhibition, and increased autonomic activity represented by cardiac changes which significantly influence prognosis.

Screening for early dementia using memory complaints from patients and relatives

This study examined whether the subjective impression of memory function might differentiate healthy elderly subjects from patients with memory complaints, and whether memory complaints differed between patients with and without a dementing illness. Both self-assessment and relatives' responses on a new memory questionnaire differentiated patient groups from control subjects. The relatives' form measuring deterioration in memory function over time identified dementing individuals from those with non-dementing causes for their memory complaints. Factor analysis indicated that patients' memory complaints correlated with depression rather than objective memory performance, while relatives' ratings correlated with objective memory scores, not depression. Stepwise discriminant function analyses showed that objective memory testing greatly improved specificity but not sensitivity of the subjective memory questionnaire alone.

Behavioral effects of iron supplementation in infants in Madang, Papua New Guinea

The effect of iron supplementation on attending behavior of 96 1-y-old infants was assessed in a double-blind, randomized, controlled trial of iron dextran in Papua New Guinea. The treatment group received an injection of iron dextran at 2 mo; the controls received a placebo injection. Because many children had malarial parasitemia at testing, presence of malaria was used in the analysis. A significant interaction was found between iron and malaria infection on total fixation time: iron-supplemented groups and placebo-treated parasitemic children showed significantly higher total fixation scores than did placebo-treated aparasitemic children. Blood analysis of iron status showed similar results, with lowest iron status evident in the placebo-treated aparasitemic group. There was no effect of treatment on rate of habituation or dishabituation. Supplemental iron treatment has a significant effect on attention but the direction of the effect depends on the presence of malaria infection.

Linear growth measurement: a comparison of single arm-lengths and arm-span

An investigation was done to determine whether the arm-lengths of 44 children with myelomeningocele differed from those of 96 control children; whether the level of the meningocele lesion has any effect on arm-length; and to compare the relationship between arm-length and both stature and age. Mean total arm-lengths did not differ significantly between the two groups of children. However, the mean arm-spans of children with high myelomeningocele lesions differed significantly from those of control children. Within the myelomeningocele group, the height of the lesion had no significant effect on any of the arm-length variables. Very high positive correlations were found between upper-arm and total arm-lengths and stature, and between arm-span and stature in the control children. These results suggest that arm-length may be used as an alternative measure of linear growth in children, and that a single arm-length will be the most accurate indicator of growth of children with myelomeningocele.

Optic neuritis and myelopathy in systemic lupus erythematosus

The optic neuritis of systemic lupus erythematosus (S.L.E.) more frequently results in the persistence of a central scotoma or complete blindness after a single attack than demyelinating optic neuritis, although the initial clinical presentations may be identical. A significant number of patients, however, recover normal vision. Optic neuritis may be the presenting symptom of S.L.E. and as myelopathy may also occur in the course of the disease, confusion with multiple sclerosis may result, especially if there are no arthritic, cutaneous nor visceral manifestations. We report a case of lupus optic neuritis associated with anticardiolipin antibodies and a circulating lupus anticoagulant and suggest these may be a marker for vasculitic optic neuritis and play a role in its aetiology.

Effect of temperature change on the sealing properties of Cavit and Cavit G

Sixty recently extracted intact anterior teeth were filled with Cavit G or Cavit. They were examined for dye penetration at room temperature and subjected to temperature change. Under the test conditions Cavit G and Cavit were resistant to penetration by aqueous methylene blue dye.

Periapical actinomycosis. An unusual case report

An unusual case of actinomycosis in the oral cavity is reported. The strict anaerobic qualities of Actinomyces israelii make laboratory culturing and growing of this organism difficult. Accordingly, the diagnosis was based on the histopathologic report. Because of the atypical clinical presentation, i.e., lack of any discharging sinus tract on the skin surface, and the histopathologic reports, it was postulated that the actinomycosis was superimposed on an existing granulomatous tissue.

Renal calculi and biochemical abnormalities. In children with myelomeningocele and heoconduit diversion

Of 38 pediatric cases of ileoconduit urinary diversion of myelomeningocele, 4 with renal calculi are presented. An increased risk of renal calculus formation may be imposed on children with myelomeningocele with ileoconduit urinary diversion especially so in functionally and anatomically abnormal kidneys and in chronic renal infection with urea-splitting bacteria. It is not clear why the ileoconduit procedure should increase the incidence of renal calculi in such children.