TECHNICAL NOTE: SOME VIEWS ON THE TREATMENT OF "ARTIFACTS" IN PSYCHOPHYSIOLOGICAL RECORDINGS

The treatment of artifactual responses in psychophysiology is rarely discussed or made explicit in research reports. The rationales and procedures of five approaches are presented: excluding the data; averaging other epochs; subjective estimation; straight-line connecting; and following the pen. Each approach is based on a somewhat different theoretical orientation, and the choice of each will depend on the researcher's theoretical preference and also the relative “costs” of losing data vs programming special instructions. Other considerations such as objectivity, consistency, and replicability are discussed.     

Attentional characteristics of infants and toddlers with Williams syndrome during triadic interactions

Two studies were conducted to consider the looking behavior of infants and toddlers with Williams syndrome (WS).In Study 1,the looking behavior of a 10-month-old girl with WS during play sessions with her mother and with a stranger was compared to that of 2 groups of infants who were developing normally (ND),1 matched for chronological age and the other for developmental age. The infant with WS spent more than twice as much time looking at her mother as the infants in either contrast group did. She also spent twice as much time looking at the stranger.In addition, during 78%of this time, her gaze at the stranger was coded as extremely intense. Looks of this intensity were virtually never made by the ND infants. In Study 2,the looking behavior of 31 individuals with WS ages 8 to 43 months during a genetics evaluation was compared to that of 319 control children in the same age range (242 with developmental delay due to causes other than WS).Twenty-three of the 25 participants with WS aged 33 months or younger demonstrated extended and intense looking at the geneticist. In contrast, none of the control participants looked extensively or intently at the geneticist. Findings are discussed in the context of previous research on arousal and focused attention during normal development and on temperament and personality of older children and adults with WS. It is argued that the unusual looking patterns evidenced by infants and toddlers with WS presage the unusual temperament and personality of older individuals with WS, and the possibility of a genetic basis for these behaviors is addressed.     

Teenagers' health concerns: implications for primary health care professionals.

Four hundred and eighty five students, aged 13-15 years, at nine comprehensive schools in the London borough of Brent completed a questionnaire about health-related behaviours and health concerns. Among general health concerns, most prominent were weight, acne, nutrition and exercise. There appeared to be a considerable unmet need to discuss sexual development, sexually transmitted diseases and contraception. A substantial proportion (16% of the girls and 3% of the boys) reported sexual abuse, but few wished to discuss this with a doctor or nurse. Although a relatively high percentage of the students smoked and a smaller percentage used alcohol or drugs regularly, there was little concern or interest in discussing these matters with a health professional. Most of the schools did not have a formal health education programme, and in none of them were health professionals available for discussion of the issues under study. There appears to be a need for more comprehensive health education in schools and for primary health care professionals, particularly general practitioners to raise these issues opportunistically with their teenage patients.     

Tumor cell-endothelial interactions. Increased adhesion of human melanoma cells to activated vascular endothelium.

The authors examined the adhesion of seven human melanoma cell lines to cultured human umbilical vein endothelial cells (HEC) that were activated by cytokines or bacterial endotoxin. The adhesion of Hs 294T and MEL-24 cells was markedly increased (approximately 2 to 12-fold) after pretreatment of HEC monolayers for 6 hours with tumor necrosis factor, interleukin-1, or endotoxin. Smaller increases were noted with the cell lines RPMI 7951, HT 144, Malme-3M, MEL-2, and no significant increase was observed with MEL-5. Cytokine and endotoxin effects on melanoma-HEC adhesion were concentration- and time-dependent, with onset by 2 hours, peak at 6-8 hours and maintenance through 48 hours. Cytokine induction of increased HEC adhesiveness for melanoma cells was blocked by actinomycin-D or cycloheximide, suggesting the requirement for RNA and protein synthesis. Interaction of melanoma cells with subendothelial matrix did not appear to play a primary role because: 1) phase contrast and electron microscopy revealed direct contact between tumor cells and endothelial cells in standardized monolayer adhesion assays; 2) increased adhesion (rosette formation) of tumor cells to activated HEC was also observed after nonenzymatic resuspension of HEC, and 3) the matrix peptide GRGDSP partially blocked (approximately 45%) Hs 294T cell adhesion to subendothelial matrix, but had little or no effect on adhesion to activated HEC monolayers. Taken together, these data suggest that inducible HEC surface changes may mediate the adhesion of certain melanoma cells, thereby exerting an active influence over the metastatic process.     

In vitro histamine release induced by radiocontrast media and various chemical analogs in reactor and control subjects

The factors governing in vitro basophil histamine release induced by radiocontrast material (RCM) were evaluated by the use of two RCMs (diatrizoate and metrizamide) and three structural analogs of RCM (benzoic acid, diaminobenzoic acid, and 3-acetamidobenzoic acid) in basophil histamine-release studies. Diatrizoate was chosen because it is a commonly used RCM and is routinely administered as a hypertonic drug (958 mOsm/kg or greater). Metrizamide is a newly synthesized RCM and is routinely administered in isotonic form (approximately 280 mOsm/kg). The analogs were used in hope of identifying any structure-function relationship that might exist between RCMs and the activation of a proposed basophil membrane receptor responsible for the induction of de granulation. In addition, results in a control group of normal subjects were compared with those in a group of patients who had experienced anaphylactoid reactions to intravenous RCM. Basophils from both groups were incubated with diatrizoate and metrizamide to assess their relative sensitivity to these drugs. Both metrizamide and diatrizoate induced in vitro histamine release. Therefore hypertonicity is not an absolute requirement for RCM-induced in vitro basophil de granulation. Although there was a trend far reagents without a prosthetic group at position 5 on the benzene ring (especially 3-acetamidobenzoic acid) to induce more release of histamine than reagents with such a prosthetic group, differences between these reagents did not reach statistical significance. Therefore no clearcut structure-function relationship could be demonstrated. “Reactor” subjects released significantly-larger percents of their intracellular histamine than did “nonreactors” (p < 0.05). Degranulated cells retained their ability to exclude trypan blue, an observation suggesting that RCM-induced histamine release does not involve cell death.     

Automatic avoidance of obstacles is a dorsal stream function: evidence from optic ataxia

When we reach out to pick something up, our arm is directed to the target by visuomotor networks in the cortical dorsal stream. However, our reach trajectories are influenced also by nontarget objects, which might be construed as potential obstacles. We tested two patients with bilateral dorsal-stream (parietal lesions, both of whom were impaired at pointing to visual stimuli (optic ataxia). We asked them to reach between two cylinders, which varied in location from trial to trial. We found that the patients' reaches remained invariant with changes in obstacle location. In a control task when they were asked to point midway between the two objects, however, their responses shifted in an orderly fashion. We conclude that the dorsal stream provides the visual guidance we automatically build into our movements to avoid potential obstacles, as well as that required to ensure arrival at the target.     

Acceleration of the Menstrual Cycle by Intercourse

Hazard statistics were applied to an extensive set of prospective data to test for an acceleration of the menstrual cycle by intercourse. Intercourse appeared to accelerate both the basal body temperature (BBT) shift and the onset of menses. Menses was accelerated more by a combination of follicular and luteal intercourse than by luteal intercourse alone (using the BBT shift as an ovulation indicator). The accelerator effects of intercourse therefore appear to cumulate across the menstrual cycle.     

Inhibition of C5 or absence of C6 protects from sepsis mortality

Inhibiting complement anaphlytoxin C5a during sepsis may prevent sepsis mortality. Although human anti-C5 antibodies exist, their therapeutic use in microbial sepsis has been avoided because of the hypothesis that inhibiting C5b will prevent formation of the bactericidal membrane attack complex (MAC) and worsen clinical outcome. We wished to test the hypothesis that inhibition of C5 would improve outcomes in sepsis. Sepsis was induced in rats by laparotomy and cecal ligation and puncture (CLP) by an IACUC-approved protocol. Sham animals underwent laparotomy without CLP. Following CLP rats were randomized to receive a single IV dose of purified IgG ant-C5 antibody (Ab) or control IgG Ab. Anti-C5 Ab treated rats (n = 20) had significantly lower mortality vs. controls (n = 21), 20% vs. 52% (P = 0.019, log-rank). Analysis of bacterial load by culture of spleen and liver homogenates showed a reduction in colony forming units in anti-C5 Ab treated rats vs. control IgG (P = 0.003 and 0.009, respectively). Anti-C5 treatment reduced lung injury as measured by total MPO content of lung tissue (P = 0.024). Finally, rats genetically deficient in C6 production, unable to form MAC but capable of producing C5a and C5b, were protected from CLP-induced sepsis mortality. Our results show that in anti-C5 antibody therapy prevents CLP sepsis-induced mortality and improves lung injury. Inhibition of the complement MAC does not increase bacterial load or mortality, therefore, the use of anti-C5 therapy may be beneficial rather than detrimental in sepsis.     

Public health monitoring of developmental disabilities with a focus on the autism spectrum disorders

Developmental disabilities (DDs) are conditions characterized by physical, cognitive, psychological, sensory, adaptive, and/or communication impairments manifested during development. Approximately 17% of individuals in the United States 18 years and younger have a DD, and for most children the cause of their condition is unknown. Of particular interest are the autism spectrum disorders (ASDs), characterized by unusual social, communication, and behavioral development. Previously autism was thought to be a rare condition, but the number of children receiving services for an ASD has increased dramatically in the last decade. Concerns about increases in DDs, particularly ASDs, their causes, and the high costs of intervention have highlighted the need for systematic public health monitoring. Service provider data, such as annual reporting of special education services or of state DD programs, do not provide a complete estimate of the rates for DDs, including ASDs. Unlike genetic metabolic disorders or congenital hearing loss (HL) for which newborn screening programs can provide accurate prevalence rates, there are currently no genetic or biologic markers for the ASDs to enable consistent and early identification of affected children. Centers for Disease Control and Prevention's (CDC) Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) is a model for population monitoring of ASDs/DDs that has been implemented in other states. This article discusses the role of ASD/DD tracking in public health, as well as the challenges of ASD/DD tracking, including case definition and identification, associated conditions, linkages, and data access.