Short-term temporal variation in PM2.5 mass and chemical composition during the Atlanta Supersite Experiment, 1999

Measurements in urban Atlanta of transient aerosol events in which PM2.5 mass concentrations rapidly rise and fall over a period of 3-6 hr are reported. The data are based on new measurement techniques demonstrated at the U.S. Environmental Protection Agency (EPA) Atlanta Supersite Experiment in August 1999. These independent instruments for aerosol chemical speciation of NO3-, SO4(2-), NH4+, and organic and elemental carbon (OC and EC), reconstructed the observed hourly dry PM2.5 mass to within 20% or better. Data from the experiment indicated that transient PM2.5 events were ubiquitous in Atlanta and were typically characterized by a sudden increase of EC (soot) and OC in the early morning or SO4(2-) in the late afternoon. The frequent temporal decoupling of these events provides insights into their origins, suggesting mobile sources in metro Atlanta as the main contributor to early morning PM2.5 and more regionally located point SO2 sources for afternoon PM2.5 events. The transient events may also have health implications. New data suggest that short-term PM2.5 exposures may lead to adverse health effects. Standard integrated filter-based techniques used in PM2.5 compliance monitoring networks and in most past PM2.5 epidemiologic studies collect samples over 24-hr periods and thus are unable to capture these transient events. Moreover, health-effects studies that focus on daily PM2.5 mass alone cannot evaluate the health implications of the unique and variable chemical properties of these episodes.

Oscillating on borrowed time: diffusible signals from immortalized suprachiasmatic nucleus cells regulate circadian rhythmicity in cultured fibroblasts

The capacity to generate circadian rhythms endogenously and to confer this rhythmicity to other cells was compared in immortalized cells derived from the suprachiasmatic nucleus (SCN) and a fibroblast line to differentiate SCN pacemaker properties from the oscillatory behavior of non-clock tissues. Only SCN2.2 cells were capable of endogenously generating circadian rhythms in 2-deoxyglucose uptake and Per gene expression. Similar to SCN function in vivo, SCN2.2 cells imposed rhythms of metabolic activity and Per gene expression on cocultured NIH/3T3 fibroblasts via a diffusible signal. The conferred rhythms in NIH/3T3 cells were phase delayed by 4-12 hr relative to SCN2.2 circadian patterns, thus resembling the phase relationship between SCN and peripheral tissue rhythms in vivo. Sustained metabolic rhythmicity in NIH/3T3 cells was dependent on continued exposure to SCN2.2-specific outputs. In response to a serum shock the NIH/3T3 fibroblasts exhibited recurrent oscillations in clock gene expression, but not in metabolic activity. These molecular rhythms in serum-shocked fibroblasts cycled in a phase relationship similar to that observed in the SCN in vivo; peak Per1 and Per2 mRNA expression preceded the rhythmic maxima in Cry1 and Cry2 mRNA levels by 4 hr. Despite these clock gene oscillations the serum-shocked NIH/3T3 cells failed to drive circadian rhythms of Per1 and Per2 expression in cocultures of untreated fibroblasts, suggesting that expression and circadian regulation of the Per and Cry genes are not sufficient to confer pacemaker function. Therefore, SCN-specific outputs are necessary to drive circadian rhythms of metabolic activity, and these output signals are not a direct product of clock gene oscillations.

Face processing occurs outside the fusiform 'face area' in autism: evidence from functional MRI

Processing the human face is at the focal point of most social interactions, yet this simple perceptual task is difficult for individuals with autism, a population that spends limited amounts of time engaged in face-to-face eye contact or social interactions in general. Thus, the study of face processing in autism is not only important because it may be integral to understanding the social deficits of this disorder, but also, because it provides a unique opportunity to study experiential factors related to the functional specialization of normal face processing. In short, autism may be one of the only disorders where affected individuals spend reduced amounts of time engaged in face processing from birth. Using functional MRI, haemodynamic responses during a face perception task were compared between adults with autism and normal control subjects. Four regions of interest (ROIs), the fusiform gyrus (FG), inferior temporal gyrus, middle temporal gyrus and amygdala were manually traced on non-spatially normalized images and the percentage ROI active was calculated for each subject. Analyses in Talairach space were also performed. Overall results revealed either abnormally weak or no activation in FG in autistic patients, as well as significantly reduced activation in the inferior occipital gyrus, superior temporal sulcus and amygdala. Anatomical abnormalities, in contrast, were present only in the amygdala in autistic patients, whose mean volume was significantly reduced as compared with normals. Reaction time and accuracy measures were not different between groups. Thus, while autistic subjects could perform the face perception task, none of the regions supporting face processing in normals were found to be significantly active in the autistic subjects. Instead, in every autistic patient, faces maximally activated aberrant and individual-specific neural sites (e.g. frontal cortex, primary visual cortex, etc.), which was in contrast to the 100% consistency of maximal activation within the traditional fusiform face area (FFA) for every normal subject. It appears that, as compared with normal individuals, autistic individuals 'see' faces utilizing different neural systems, with each patient doing so via a unique neural circuitry. Such a pattern of individual-specific, scattered activation seen in autistic patients in contrast to the highly consistent FG activation seen in normals, suggests that experiential factors do indeed play a role in the normal development of the FFA.

Face processing occurs outside the fusiform 'face area' in autism: evidence from functional MRI

Processing the human face is at the focal point of most social interactions, yet this simple perceptual task is difficult for individuals with autism, a population that spends limited amounts of time engaged in face-to-face eye contact or social interactions in general. Thus, the study of face processing in autism is not only important because it may be integral to understanding the social deficits of this disorder, but also, because it provides a unique opportunity to study experiential factors related to the functional specialization of normal face processing. In short, autism may be one of the only disorders where affected individuals spend reduced amounts of time engaged in face processing from birth. Using functional MRI, haemodynamic responses during a face perception task were compared between adults with autism and normal control subjects. Four regions of interest (ROIs), the fusiform gyrus (FG), inferior temporal gyrus, middle temporal gyrus and amygdala were manually traced on non-spatially normalized images and the percentage ROI active was calculated for each subject. Analyses in Talairach space were also performed. Overall results revealed either abnormally weak or no activation in FG in autistic patients, as well as significantly reduced activation in the inferior occipital gyrus, superior temporal sulcus and amygdala. Anatomical abnormalities, in contrast, were present only in the amygdala in autistic patients, whose mean volume was significantly reduced as compared with normals. Reaction time and accuracy measures were not different between groups. Thus, while autistic subjects could perform the face perception task, none of the regions supporting face processing in normals were found to be significantly active in the autistic subjects. Instead, in every autistic patient, faces maximally activated aberrant and individual-specific neural sites (e.g. frontal cortex, primary visual cortex, etc.), which was in contrast to the 100% consistency of maximal activation within the traditional fusiform face area (FFA) for every normal subject. It appears that, as compared with normal individuals, autistic individuals 'see' faces utilizing different neural systems, with each patient doing so via a unique neural circuitry. Such a pattern of individual-specific, scattered activation seen in autistic patients in contrast to the highly consistent FG activation seen in normals, suggests that experiential factors do indeed play a role in the normal development of the FFA.

Atypical patterns of cerebral motor activation in autism: a functional magnetic resonance study

BACKGROUND

Early neurodevelopmental pathogenesis in autism potentially affects emerging functional maps, but little imaging evidence is available.

METHODS

We studied eight male autistic and eight matched normal subjects, using functional magnetic resonance imaging during visually paced finger movement, compared to a control condition (visual stimulation in the absence of motor response).

RESULTS

Groupwise analyses showed activation in contralateral perirolandic cortex, basal ganglia, and thalamus, bilateral supplementary motor area, and ipsilateral cerebellum for both groups. However, activations were less pronounced in the autism group. Direct group comparisons demonstrated greater activation in perirolandic and supplementary motor areas in the control group and greater activation (or reduced deactivation) in posterior and prefrontal cortices in the autism group. Intraindividual analyses further showed that strongest activations were consistently located along the contralateral central sulcus in control subjects but occurred in locations differing from individual to individual in the autism group.

CONCLUSIONS

Our findings, though based on a rather small sample, suggest abnormal individual variability of functional maps and less distinct regional activation/deactivation patterns in autism. The observations may relate to known motor impairments in autism and are compatible with the general hypothesis of disturbances of functional differentiation in the autistic cerebrum.

Attention function and dysfunction in autism

Impairments of attention are among the most consistently reported cognitive deficits in autism, and they continue to be a key focus of research. This is in no doubt due to the importance of normal attention function to the development of many so-called "higher level" cognitive operations, and to the likely involvement of attention dysfunction in certain clinical features of autism. Autistic individuals display a wide range of attentional abilities and deficits across the many domains of attention function, including selective, sustained, spatial, and shifting attention operations. This unique pattern of attention function and dysfunction has profound implications for the development and treatment of autistic children. The present review will explore this pattern of attentional strengths and weaknesses and the neural defects that underlie them.

Echocardiographic texture analysis using the wavelet transform: differentiation of early heart muscle disease

Echocardiographic quantitation of myocardial texture for diagnosis of early cardiomyopathy (CMP) remains problematic. Conventional statistical methods are limited, contributed by a small image region-of-interest (ROI) and difficulty in discrimination from noise. This study was performed to evaluate the 2-D Haar wavelet decomposition method as a tool to identify textural changes in a rat model of early CMP, focusing on changes that occur before development of M-mode structural abnormalities. Early diabetic CMP, ethanol CMP and diabetic-ethanol CMP rat models were evaluated. Echocardiography was performed on two groups of rats. Group I (5 week cohort, n = 4 per subgroup) included controls, rats on 12% ethanol, a diabetic subgroup, and diabetic rats on 4% ethanol. Group II (10 week cohort, n = 5 per subgroup) included the same categories as group I with an additional subgroup taking 4% ethanol was also studied. M-mode left ventricular measurements were comparable in all subgroups of group I. However, diabetic rats in group II had an increased left ventricular dimension (LVD) compared to all others and an increased septal dimension (IVSD) and posterior wall dimension (PWD) were noted in the 4% and 12% ethanol groups. End-diastolic digital images of all rats in the parasternal short axis view, at the papillary muscle level, were downloaded to a computer. A 16 x 16 (ROI) was selected from the anterior interventricular septum. Although standard statistical methods could not differentiate any of the groups, calculation of textural energy and normalized textural energy with the 2-D Haar wavelet decomposition method found at 5 weeks increased normalized texture energy in diabetics compared to all others. At 10 weeks increased texture energy was noted in diabetics. Diabetic-ethanol rats at both 5 and 10 weeks revealed a blunted textural energy compared to diabetic rats. In a rat model of diabetic cardiomyopathy, the 2-D wavelet decomposition method identified textural energy changes before development of echocardiographic structural changes. Ethanol-associated blunting of textural changes in diabetic rats was also noted. This method for quantitation of ventricular texture may be relevant for diagnosis of early cardiomyopathy.

Feelings of knowing in the Ranschburg effect

In two experiments, we assessed feelings of knowing (FOKs) for the Ranschburg effect to examine the types of retrieval ease that affect FOKs. In the Ranschburg effect, retrieval performance for repeated items differs from nonrepeated items in supramemory span tasks. We found that FOKs are affected by memory manipulations that affect recall processes, but not by manipulations that affect recognition. This suggests that processes that affect recognition, such as target familiarity, do not affect FOKs, whereas processes that affect recall, such as response suppression and guessing factors, affect FOKs. We propose that an integrated theory of FOKs must include mechanisms responsive to both encoding and retrieval factors (such as retrieval accessibility and cue familiarity), which are highly susceptible to output interference.

Mapping of a gene for severe pediatric gastroesophageal reflux to chromosome 13q14

CONTEXT

Gastroesophageal reflux (GER) has not previously been widely regarded as a hereditary disease. A few reports have suggested, however, that a genetic component may contribute to the incidence of GER, especially in its severe or chronic forms.

OBJECTIVE

To identify a genetic locus that cosegregates with a severe pediatric GER phenotype in families with multiple affected members.

DESIGN

A genome-wide scan of families affected by severe pediatric GER using polymorphic microsatellite markers spaced at an average of 8 centimorgans (cM), followed by haplotyping and by pairwise and multipoint linkage analyses.

SETTING

General US community, with research performed in a university tertiary care hospital.

SUBJECTS

Affected and unaffected family members from 5 families having multiple individuals affected by severe pediatric GER, identified through a patient support group.

MAIN OUTCOME MEASURES

Determination of inheritance patterns and linkage of a genetic locus with the severe pediatric GER phenotype by logarithm-of-odds (lod) score analysis, considering a lod score of 3 or greater as evidence of linkage.

RESULTS

In these families, severe pediatric GER followed an autosomal dominant hereditary pattern with high penetrance. A gene for severe pediatric GER was mapped to a 13-cM region on chromosome 13q between microsatellite markers D13S171 and D13S263. A maximum multifamily 2-point lod score of 5.58 and a maximum multifamily multipoint lod score of 7.15 were obtained for marker D13S1253 at map position 35 cM when presumptively affected persons were modeled as unknown (a maximum multipoint score of 4.88 was obtained when presumptively affected persons were modeled as unaffected).

CONCLUSION

These data suggest that a gene for severe pediatric GER maps to chromosome 13q14. JAMA. 2000;284:325-334

Method comparisons for particulate nitrate, elemental carbon, and PM2.5 mass in seven U.S. cities

Methods that measure PM2.5 mass, total particulate NO3-, and elemental carbon (EC) were evaluated in seven U.S. cities from 1997 to 1999. Sampling was performed in Bakersfield, CA; Boston, MA; Chicago, IL; Dallas, TX; Philadelphia, PA; Phoenix, AZ; and Riverside, CA. Evaluating and validating methods that measure the components of fine mass are important to the effort of establishing a speciation-monitoring network. The Harvard Impactor (HI), which measures fine particle mass, showed excellent agreement (r2 = 0.99) with the PM2.5 Federal Reference Method (FRM) for 81 24-hr samples in Riverside and Bakersfield. The HI also showed good precision (4.8%) for 243 24-hr collocated samples over eight studies. The Aethalometer was employed in six of the sampling locations to measure black carbon (BC). These values were compared to EC as measured from a quartz filter using thermal analysis. For the six cities combined, the two methods were highly correlated (r2 = 0.94; 187 24-hr samples); however, the BC values were approximately 24% less than the EC measurements consistently across all six cites. This compares well to results observed for EC/BC measurements observed in other semi-urban areas. Particulate NO3- was measured using the Harvard-EPA Annular Denuder System (HEADS). This was compared to the NO3- measured from the HI Teflon (DuPont) filter to assess NO3- artifacts. Significant NO3- losses (approximately 50% of total NO3-) were found in Riverside, Philadelphia, and Boston, while minimal artifacts were observed in the other sites. Two types of HEADS configurations were employed in five cities. One system used a Na2CO3-coated glass fiber filter, and the other type used a nylon filter to collect volatilized NO3- from the Teflon filter. The HEADS with the Na2CO3-coated filter consistently underestimated the total particulate NO3- by approximately 20% compared to the nylon HEADS.

Maximizing nurses' advocacy role to improve patient outcomes

Perioperative nurses are eminently situated, academically prepared, and professionally qualified to positively affect patient outcomes. Increasing efficiency and justifying the need for an RN in the perioperative milieu revolve around nurses' role as patient advocates. Perioperative nurses can take many measures to maximize this role, including reducing surgical site infections by enabling the timely administration of antimicrobial prophylaxis and by ensuring that surgical staff members realize the documented risks of removing hair from the surgical site.

Avoiding the fraud and abuse pitfalls

In the current medical environment, long-standing and appropriate referral patterns among medical care providers may be scrutinized for possible violation of a technical provision of Medicare, the "anti-fraud and abuse statute." The physician can avoid misunderstanding by preparing and implementing a compliance program.

Role of brain-derived neurotrophic factor in the circadian regulation of the suprachiasmatic pacemaker by light

The central pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus mediates the generation of mammalian circadian rhythms, including an oscillation in pacemaker sensitivity to photic signals conveyed by the retinohypothalamic tract. Because brain-derived neurotrophic factor (BDNF) has been implicated in the functional regulation of neural input to other targets of visual pathways, the present study examined whether changes in BDNF expression or blockade of its action in the SCN affect circadian pacemaker responses to light. In rats receiving infusion of exogenous BDNF into the SCN, the free-running rhythm of activity in constant darkness was characterized by large phase advances in response to light exposure during the midsubjective day, when the circadian pacemaker is normally insensitive to photic perturbation. In contrast, SCN infusion of BDNF did not potentiate either phase-delaying or phase-advancing effects of light on the rat activity rhythm during the subjective night. In heterozygous BDNF mutant mice, deficits and damped rhythmicity in SCN levels of this neurotrophin were accompanied by marked decreases in the amplitude of light-induced phase shifts during the subjective night. In agreement with the effects of decreased BDNF expression, SCN infusion of the tyrosine kinase inhibitor K252a blocked or strongly inhibited both the phase-delaying and -advancing effects of light during the subjective night. Collectively, these findings suggest that BDNF-mediated signaling may play an important role in the circadian regulation of SCN pacemaker sensitivity to light.

Ambient pollution and heart rate variability

BACKGROUND

We investigated associations between ambient pollution levels and cardiovascular function in a repeated measures study including 163 observations on twenty-one 53- to 87-year-old active Boston residents observed up to 12 times from June to September 1997. Particles with aerodynamic diameter </=2.5 microm (PM(2.5)) were measured continuously using a tapered element oscillating microbalance.

METHODS AND RESULTS

The protocol involved 25 minutes per week of continuous Holter ECG monitoring, including 5 minutes of rest, 5 minutes of standing, 5 minutes of exercise outdoors, 5 minutes of recovery, and 20 cycles of slow breathing. Heart rate variability (HRV) was assessed through time domain variables: the standard deviation of normal RR intervals (SDNN) and the square root of the mean of the squared differences between adjacent normal RR intervals (r-MSSD). Mean 4-hour PM(2.5) levels ranged from 3 to 49 microg/m(3); 1-hour ozone levels ranged from 1 to 77 ppb. In multivariate analyses, significantly less HRV (SDNN and r-MSSD) was associated with elevated PM(2.5). During slow breathing, a reduction in r-MSSD of 6.1 ms was associated with an interquartile (14.3 microg/m(3)) increase in PM(2.5) during the hour of and the 3 hours previous to the Holter session (P=0.006). During slow breathing, a multiple pollution model was associated with a reduction in r-MSSD of 5.4 ms (P=0.02) and 5.5 ms (P=0.03) for interquartile changes in PM(2.5) and ozone, respectively, resulting in a combined effect equivalent to a 33% reduction in the mean r-MSSD.

CONCLUSIONS

Particle and ozone exposure may decrease vagal tone, resulting in reduced HRV.

Characterization of indoor particle sources: A study conducted in the metropolitan Boston area

An intensive particle monitoring study was conducted in homes in the Boston, Massachusetts, area during the winter and summer of 1996 in an effort to characterize sources of indoor particles. As part of this study, continuous particle size and mass concentration data were collected in four single-family homes, with each home monitored for one or two 6-day periods. Additionally, housing activity and air exchange rate data were collected. Cooking, cleaning, and the movement of people were identified as the most important indoor particle sources in these homes. These sources contributed significantly both to indoor concentrations (indoor-outdoor ratios varied between 2 and 33) and to altered indoor particle size distributions. Cooking, including broiling/baking, toasting, and barbecuing contributed primarily to particulate matter with physical diameters between 0.02 and 0.5 microm [PM((0.02-0.5))], with volume median diameters of between 0.13 and 0.25 microm. Sources of particulate matter with aerodynamic diameters between 0.7 and 10 microm [PM((0.7-10))] included sautéing, cleaning (vacuuming, dusting, and sweeping), and movement of people, with volume median diameters of between 3 and 4.3 microm. Frying was associated with particles from both PM((0.02-0.5)) and PM((0.7-10)). Air exchange rates ranged between 0.12 and 24.3 exchanges/hr and had significant impact on indoor particle levels and size distributions. Low air exchange rates (< 1 exchange/hr) resulted in longer air residence times and more time for particle concentrations from indoor sources to increase. When air exchange rates were higher (> 1 exchange/hr), the impact of indoor sources was less pronounced, as indoor particle concentrations tracked outdoor levels more closely.

Air pollution and incidence of cardiac arrhythmia

Air pollution episodes have been associated with increased cardiovascular hospital admissions and mortality in time-series studies. We tested the hypothesis that patients with implanted cardioverter defibrillators experience potentially life-threatening arrhythmias after such air pollution episodes. We compared defibrillator discharge interventions among 100 patients with such devices in eastern Massachusetts, according to variations in concentrations of particulate matter, black carbon, and gaseous air pollutants that were measured daily for the years 1995 through 1997. A 26-ppb increase in nitrogen dioxide was associated with increased defibrillator interventions 2 days later (odds ratio = 1.8; 95% confidence interval = 1.1-2.9). Patients with ten or more interventions experienced increased arrhythmias in association with nitrogen dioxide, carbon monoxide, black carbon, and fine particle mass. These results suggest that elevated levels air pollutants are associated with potentially life-threatening arrhythmia leading to therapeutic interventions by an implanted cardioverter defibrillator.

A comparison of a computer and pencil and paper assignment

Colleges are challenged to provide students with diverse teaching-learning experiences. Educators who introduce new teaching-learning experiences must evaluate the outcomes of these experiences. Three faculty members instituted a new multimedia computer-based assignment for undergraduate nursing students enrolled in a pediatric clinical course and then evaluated their knowledge and satisfaction. Students were asked to design a computer program about peripherally inserted central catheters, and to complete tests and summaries. During two semesters, 45 students participated in the assignment. As compared to another group of students who were asked to participate in a pencil and paper independent study assignment, these students were more satisfied with their computer assignment. Students in both groups, however, produced thought-provoking work and improved their knowledge base about central catheters. In many ways, the results support the use of a computer assignment.

2-chloro-3-substituted-1,4-naphthoquinone inactivators of human cytomegalovirus protease

A random screening approach has identified 2-chloro-3-substituted-1,4-naphthoquinones as potent inactivators of HCMV protease. Enzyme inactivation is due to modification of Cys202. Two of the most potent compounds maintain activity against HCMV in a plaque reduction assay.

Non-thiazolidinedione antihyperglycaemic agents. Part 3: The effects of stereochemistry on the potency of alpha-methoxy-beta-phenylpropanoic acids

Rhizopus delemar lipase catalysed ester hydrolysis of the alpha-methoxy-beta-phenylpropanoate 1 affords the (R)-(+) and (S)-(-) isomers in > 84% enantiomeric excess. Absolute stereochemistry was determined by a single crystal X-ray analysis of a related synthetic analogue. The activity of these two enantiomers on glucose transport in vitro and as anti-diabetic agents in vivo is reported and their unexpected equivalence attributed to an enzyme-mediated stereospecific isomerisation of the (R)-(+) isomer. Binding studies using recombinant human PPARgamma (peroxisomal proliferator activated receptor gamma), now established as a molecular target for this compound class, indicate a 20-fold higher binding affinity for the (S) antipode relative to the (R) antipode.

Particulate matter, sulfur dioxide, and pulmonary function in never-smoking adults in Chongqing, China

Chongquing is one of the most polluted cities in China. To study the respiratory health effects of air pollution for this city, the authors monitored the ambient levels of particulate matter (PM2.5) and sulfur dioxide (SO2) in urban and suburban areas and performed pulmonary function testing on 1,075 adults 35 to 60 years of age who had never smoked and did not use coal stoves for cooking or heating. The mean concentration of SO2 in the urban areas (213 micrograms/m3) was twice as high as that in suburban areas (103 micrograms/m3). Mean PM2.5 levels were high in both urban (143 micrograms/m3) and suburban (139 micrograms/m3) areas. A generalized additive model was used to estimate the differences between the two areas in FEV1, FVC, and FEV1/FVC%, with adjustment for potential confounding factors, including sex, age, height, education, passive smoking, and occupational exposures to dust, gas, or fumes. Estimated differences in FEV1 between the urban and suburban areas were 199 mL (SE = 50 mL) for men and 87 mL (SE = 30 mL) for women, both statistically significant. When the men and women were pooled, the estimated difference in FEV1 was 126 mL (SE = 27 mL). Similar trends were observed for FVC and FEV1/FVC%. After exclusion of 104 subjects with histories of occupational exposures to dust, gas, or fumes, the estimated difference was some-what smaller than that of the total samples. However, the effects on FEV1 and FEV1/FVC% remained significant for both men and women.

The impact of assertive community treatment on the social relationships of people who are homeless and mentally ill

Two randomized experiments compared the effectiveness of the assertive community treatment (ACT) team against other treatments (outpatient therapy, drop-in center, and brokered case management) in improving the social relationships of individuals who were both homeless and suffered from severe and persistent mental illness. In both studies clients assigned to ACT teams reported having more professionals in their social networks than clients assigned to the other treatments. Clients did not report significant differences between treatment conditions on most of the other social relationship dimensions. Further attention to developing social skills and network interventions within ACT teams are recommended.

Aggressive pituitary tumors

Although almost all pituitary tumors are benign adenomas, a surprisingly large number of these tumors invade tissues outside of the pituitary gland. Such invasion, by itself, is not diagnostic of pituitary carcinomas, which are exceedingly rare (0.13% of 2,342 pituitary tumors in one series). Several different criteria are available to determine whether a tumor is invasive. Intraoperative biopsies demonstrate an 85% incidence of microscopic invasion of the dura. Evidence of gross invasion at surgery and radiologic evidence of invasion on magnetic resonance imaging (MRI) and computed tomographic (CT) scans occur at a much lower incidence but may be more predictive of surgical cure. Invasive adenomas also have higher proliferation rates than do noninvasive adenomas, as shown by immunohistochemical detection of proliferating cell nuclear antigen (PCNA), Ki-67, and MIB-1. The expression of p53, increased epidermal growth factor receptors, and protein kinase C activity also correlate with invasion and aggressive behavior. Clinically significant invasion is more frequent with macroadenomas. Macroadenomas of all pituitary tumor subtypes except gonadotroph macroadenomas have a greater than 50% incidence of gross invasion. Currently, there is no accepted means of predicting an adenoma's clinically significant invasiveness and long-term aggressiveness.

Effect of rimantadine treatment on clinical manifestations and otologic complications in adults experimentally infected with influenza A (H1N1) virus

Susceptible adults (n = 105) were enrolled into a randomized double-blind study of rimantadine treatment of experimental influenza A infection. Subjects were cloistered for 8 days and challenged with a rimantadine-sensitive strain of influenza A H1N1 virus at the end of the first day. Forty-eight hours after challenge and for 8 days, 54 subjects received placebo and 51 received rimantadine (100 mg orally, twice a day). Symptoms, signs, and pathophysiologies were monitored. Nine subjects were not infected. Seventeen subjects (38%) in the rimantadine and 26 (53%) in the placebo group became ill. A beneficial effect of rimantadine was documented for virus shedding, symptom load, and sinus pain. Rimantadine had no effect on nasal patency, mucociliary clearance, nasal signs, or on symptoms and signs of otologic complications. These results do not support a preventive effect of rimantadine on the development of otologic manifestations of influenza A infection in adults.

The peripheral giant cell granuloma

A peripheral giant cell granuloma can be seen as a pedunculated or broad-based lesion. Such lesions occur after age 20 years, with 50 percent of patients 40 to 59 years old. Frequently, there is a history of trauma to the region.

Traumatic reactions as predictors of posttraumatic stress six months after the Oklahoma City bombing

OBJECTIVE

This study attempted to identify remembered reactions of Oklahoma City residents at the time of the April 1995 terrorist bombing that predicted later development of posttraumatic stress symptoms.

METHODS

Eighty-six adults who sought help for distress related to the bombing six months after it occurred completed a survey about demographic characteristics, level of exposure to the event, symptoms of grief, retrospective reports of reactions at the time of the trauma, current posttraumatic stress symptoms, and coping strategies. To identify immediate bombing reactions predictive of later distress, retrospective reports of reactions to the trauma were correlated with current posttraumatic stress symptoms. Multiple regression analysis was used to determine which reactions predicted the emergence of posttraumatic stress symptoms.

RESULTS

Reactions of being nervous and being upset by how other people acted when the bombing occurred accounted for about one-third of the total variation in posttraumatic stress symptom scores and thus were major predictors of posttraumatic stress.

CONCLUSIONS

These results differ from those of other studies in which peritraumatic dissociation, or dissociation at the time of the event, was more predictive than anxiety for developing later distress. The results suggest that persons who experience significant anxiety at the time of the traumatic event may continue to experience distress. Those who are overly concerned about others' actions may be showing diminished interpersonal trust, evidence of terrorism's ability to erode social harmony.

Evaluation of the TEOM method for measurement of ambient particulate mass in urban areas

Increased interest in the health effects of ambient particulate mass (PM) has focused attention on the evaluation of existing mass measurement methodologies and the definition of PM in ambient air. The Rupprecht and Patashnick Tapered Element Oscillating MicroBalance (TEOM) method for PM is compared with time-integrated gravimetric (manual) PM methods in large urban areas during different seasons. Comparisons are conducted for both PM10 and PM2.5 concentrations. In urban areas, a substantial fraction of ambient PM can be semi-volatile material. A larger fraction of this component of PM10 may be lost from the TEOM-heated filter than the Federal Reference Method (FRM). The observed relationship between TEOM and FRM methods varied widely among sites and seasons. In East Coast urban areas during the summer, the methods were highly correlated with good agreement. In the winter, correlation was somewhat lower, with TEOM PM concentrations generally lower than the FRM. Rubidoux, CA, and two Mexican sites (Tlalnepantla and Merced) had the highest levels of PM10 and the largest difference between TEOM and manual methods. PM2.5 data from collocation of 24-hour manual samples with the TEOM are also presented. As most of the semi-volatile PM is in the fine fraction, differences between these methods are larger for PM2.5 than for PM10.

Prediction and preparation, fundamental functions of the cerebellum

Collapse

Attentional activation of the cerebellum independent of motor involvement

The cerebellum traditionally has been viewed as a neural device dedicated to motor control. Although recent evidence shows that it is involved in nonmotor operations as well, an important question is whether this involvement is independent of motor control and motor guidance. Functional magnetic resonance imaging was used to demonstrate that attention and motor performance independently activate distinct cerebellar regions. These findings support a broader concept of cerebellar function, in which the cerebellum is involved in diverse cognitive and noncognitive neurobehavioral systems, including the attention and motor systems, in order to anticipate imminent information acquisition, analysis, or action.

Effect of percutaneous local anaesthetics on pain reduction during pulse dye laser treatment of portwine stains

We have used EMLA, 4% amethocaine gel and placebo for facial portwine stains, for a period of 1 h, in a double-blind study. After removal of the preparations from the skin surface, each area was treated with six pulses of the laser, each 5 mm in diameter. Any pain noted immediately after treatment was recorded using both visual analogue (VAS) and verbal rating (VRS) scores. Twenty nine patients completed the study and statistical analysis of the results indicated that both EMLA and 4% amethocaine gel were superior to placebo (P < 0.001). However, when EMLA and 4% amethocaine gel were compared, the amethocaine preparation was significantly better (P < 0.05, VAS; P < 0.005 VRS) than EMLA in reducing pain caused by the laser treatment.

A PET study of Turner's syndrome: effects of sex steroids and the X chromosome on brain

Women with Turner's syndrome (TS) allow us to study the neurobiological associates of cognitive and behavioral abnormalities because they lack one/part of one X chromosome, and endogenous estrogen. We studied 13 healthy controls (mean age +/- SD, 28 +/- 6 years) and 16 TS subjects (mean age +/- SD, 26 +/- 6 years). We measured cognitive abilities using neuropsychological tests, and cerebral metabolic rates for glucose with positron emission tomography. Compared to controls, TS subjects had significant absolute hypermetabolism in most brain areas; however, normalized metabolism was significantly lower in TS subjects than controls in the insula and association neocortices bilaterally, and there were significant differences in functional metabolic associations of brain region pairs originating in occipital cortex bilaterally, and within the right hemisphere. There were significant correlations between right-left cognitive and metabolic asymmetries in the TS group. Also, within TS a preliminary analysis demonstrated "X chromosome dosage" effects in language ability and left temporal metabolism, asymmetry of right-left test scores, and parietal metabolism. We hypothesize that within TS: i) generalized brain hypermetabolism reflects global abnormalities in neuron packing; ii) neuronal abnormalities occur in association neocortex that differ in nature or extent from whole brain and are associated with significant differences in normalized metabolism; iii) cognitive deficits are related to brain metabolic abnormalities; and iv) social-behavioral problems may be related to abnormalities of brain metabolism. Moreover, in human brain the X chromosome involved in development of the association neocortices.

Squash racquets. A review of physiology and medicine

Squash is a moderate to high intensity sport which demands specific fitness. Squash at any level places a high demand on the aerobic system for energy delivery during play and recovery. In addition, the sport requires bursts of intense, anaerobic physical activity involving the lactic anaerobic energy system. Players must possess appropriate levels of local muscular endurance, strength, power, flexibility and speed, combined with agility, balance and co-ordination. Irrespective of the standard of play, aerobic fitness training and specific anaerobic training should be undertaken by all who play or intend to play squash. Aerobic fitness for the individual who is new to the game and has little training background can be improved using low intensity continuous running. Training sessions and matches should be preceded by warm-up and flexibility exercises which may reduce the chance of injury and enhance readiness to perform. Despite squash being an indoor sport, it is likely that play in hot and humid weather may generate significant thermal loads with the associated elevations in heart rate. Fluid losses of 2 L/min and rectal temperatures of 39 degrees C may occur, thereby increasing the cardiovascular stress of participation and the risk of heat illness. Sudden death and other manifestations of heart disease can occur in squash, therefore advice regarding the safe participation for those with, or who have the potential to develop disease appears essential. For those under 40 years of age who are well and have no known heart disease, medical clearance is not mandatory prior to taking up squash; for such individuals, regular medical monitoring may be unnecessary. For healthy individuals older than 40 years of age irrespective of health status, but particularly for those with coronary disease or relevant risk factors, a medical checkup is recommended prior to, and at least annually after taking up squash. Healthy individuals older than 40 years of age with one or more risk factors require a medical checkup prior to commencing squash for the first time and at regular intervals (every 2 years) thereafter. These individuals should also have a medically supervised exercise test. Those individuals older than 40 years of age who have a known history of heart disease, most commonly coronary artery disease, may play squash if it is demonstrated that, on examination or following therapy or surgery, they can exercise safely to a high workload. Most eye injuries which occur in squash are related to eye/ball and eye/racquet contact. The incidence of injury is very low but such injuries may be totally preventable. Ideally, all players should wear protective eye apparatus. The "ideal' protective apparatus should comply with the Australian/New Zealand Standard for eye protectors for racquet sports. It should be recognised at the outset that there is a paucity of specific data regarding squash and pregnancy. Most women with normal pregnancies may continue to exercise and play squash particularly in the early stages of pregnancy but should notify their physician of their intention to do so. Musculo-skeletal injuries to the lower limb dominate most studies and common injuries include sprains and strains to the back and ankles. Of particular interest is the development of degenerative hip disease in elite squash players necessitating retirement or curtailment of activity in the third decade. Dealing with injuries and illness that are attributed to squash requires an approach based on prevention as well as on appropriate injury management.

Specific cleavage of histidine-containing peptides by copper(II)

Copper(II) cleaves with moderate specificity peptides containing Ser-His or Thr-His sequences, at the N-terminal side of the hydroxyaminoacyl residue. The reaction is slow, and is first-order in peptide: CuII complex, with a half-life of several hours at 62 degrees C in sodium bicarbonate buffer, pH 8. Cleavage of other histidine-containing peptides also occurs, at a rate around 10-100-fold less. EDTA completely quenches the cleavage. The reaction is stoichiometric in CuII and is inhibited by amine-containing buffer components; Tris at 19 mM inhibits cleavage by 50%. The reaction has a complex pH-dependence, being very slow below pH 5, and with rates increasing with pH from pH 7 to pH 9.5. Slower degradative side reactions do occur, with destruction of tyrosine residues, particularly in the presence of high concentrations of chloride ion, but the specific cleavage appears to be a hydrolysis, as determined by amino-acid analysis and mass spectrometry of the products. The cleavage is clearly different from the previously described oxidative degradation of proteins catalysed by copper ions. Cleavage of denatured IgG protein occurs with sufficient specificity to reveal distinct bands on SDS-polyacrylamide gel electrophoresis under reducing conditions.

Specific cleavage of immunoglobulin G by copper ions

The hinge region of a recombinant-DNA-produced human IgG1 (Campath 1H) is specifically cleavable at a single copper-sensitive peptide bond, yielding a distinct fragment resolved by size-exclusion high-performance liquid chromatography. This novel metal ion-catalysed cleavage at slightly alkaline pH is inhibited by EDTA and its rate is reduced at slightly acidic conditions (pH 5-6) and accelerated by increasing concentrations of cupric ion and higher temperature. Complete cleavage was observed after incubation at pH 8 for 24 h with 1 mM CuCl2. Sequence analysis determined the cleavage site to be the Lys226-Thr227 bond in the hinge-region sequence DKTHT. Cleavage of other IgGs was observed to varying degrees, and specific cleavage of synthetic peptides containing this pentapeptide sequence was also observed.

Expression and purification of recombinant, glycosylated human interferon alpha 2b in murine myeloma NSo cells

We have expressed recombinant human interferon-alpha 2b in mammalian cells and isolated cell lines constitutively secreting very high levels of biologically active protein. The expression system takes advantage of the strong human cytomegalovirus immediate early promoter in mouse myeloma NSo cells and glutamine synthetase as a selectable marker; spontaneous mutants with amplified gene copy numbers were selected by growth of primary transfectants in the presence of methionine sulfoximine. Using this procedure, we have isolated a recombinant NSo cell line which secretes human interferon at the rate of 20 micrograms/10(6) cells/24 h and accumulates up to 120 micrograms/ml (approximately 2.4 x 10(7) U/ml) following prolonged undiluted culture. The interferon (IFN) could be efficiently purified on a polyclonal bovine anti-human IFN alpha specific antibody column and the glycosylation pattern was found to be similar to that of nonrecombinant IFN alpha 2b purified from virus-induced human Namalwa cells. The biological activity of the recombinant material was indistinguishable from that of natural IFN from Namalwa cells, and the specific antiviral activity, as assayed on human HeLa cells challenged with encephalomyocarditis virus, was 2 x 10(8) IU/mg, similar to that of nonrecombinant IFN preparations. This represents the highest reported level of glycosylated, recombinant IFN expression in a stable mammalian system and is a significant advance in the large-scale production of these clinically important cytokines.