Healthcare utilization and clinical characteristics of genetic epilepsy in electronic health records

Understanding the clinical characteristics and medical treatment of individuals affected by genetic epilepsies is instrumental in guiding selection for genetic testing, defining the phenotype range of these rare disorders, optimizing patient care pathways and pinpointing unaddressed medical need by quantifying healthcare resource utilization. To date, a matched longitudinal cohort study encompassing the entire spectrum of clinical characteristics and medical treatment from childhood through adolescence has not been performed. We identified individuals with genetic and non-genetic epilepsies and onset at ages 0-5 years by linkage across the Cleveland Clinic Health System. We used natural language processing to extract medical terms and procedures from longitudinal electronic health records and tested for cross-sectional and temporal associations with genetic epilepsy. We implemented a two-stage design: in the discovery cohort, individuals were stratified as being 'likely genetic' or 'non-genetic' by a natural language processing algorithm, and controls did not receive genetic testing. The validation cohort consisted of cases with genetic epilepsy confirmed by manual chart review and an independent set of controls who received negative genetic testing. The discovery and validation cohorts consisted of 503 and 344 individuals with genetic epilepsy and matched controls, respectively. The median age at the first encounter was 0.1 years and 7.9 years at the last encounter, and the mean duration of follow-up was 8.2 years. We extracted 188,295 Unified Medical Language System annotations for statistical analysis across 9659 encounters. Individuals with genetic epilepsy received an earlier epilepsy diagnosis and had more frequent and complex encounters with the healthcare system. Notably, the highest enrichment of encounters compared with the non-genetic groups was found during the transition from paediatric to adult care. Our computational approach could validate established comorbidities of genetic epilepsies, such as behavioural abnormality and intellectual disability. We also revealed novel associations for genitourinary abnormalities (odds ratio 1.91, 95% confidence interval: 1.66-2.20, P = 6.16 × 10-19) linked to a spectrum of underrecognized epilepsy-associated genetic disorders. This case-control study leveraged real-world data to identify novel features associated with the likelihood of a genetic aetiology and quantified the healthcare utilization of genetic epilepsies compared with matched controls. Our results strongly recommend early genetic testing to stratify individuals into specialized care paths, thus improving the clinical management of people with genetic epilepsies.

Contrasting Views of Autism Spectrum Traits in Adults, Especially in Self-Reports vs. Informant-Reports for Women High in Autism Spectrum Traits

There is uncertainty among researchers and clinicians about how to best measure autism spectrum dimensional traits in adults. In a sample of adults with high levels of autism spectrum traits and without intellectual disability (probands, n = 103) and their family members (n = 96), we sought to compare self vs. informant reports of autism spectrum-related traits and possible effects of sex on discrepancies. Using correlational analysis, we found poor agreement between self- and informant-report measures for probands, yet moderate agreement for family members. We found reporting discrepancy was greatest for female probands, often self-reporting more autism-related behaviors. Our findings suggest that autism spectrum traits are often underrecognized by informants, making self-report data important to collect in clinical and research settings.

Investigating the relationships between resilience, autism-related quantitative traits, and mental health outcomes among adults during the COVID-19 pandemic

Resilience is a dynamic process through which people adjust to adversity and buffer anxiety and depression. The COVID-19 global pandemic has introduced a shared source of adversity for people across the world, with detrimental implications for mental health. Despite the pronounced vulnerability of autistic adults to anxiety and depression during the COVID-19 pandemic, relationships among autism-related quantitative traits, resilience, and mental health outcomes have not been examined. As such, we aimed to describe the relationships between these traits in a sample enriched in autism spectrum-related quantitative traits during the COVID-19 pandemic. We also aimed to investigate the impact of demographic and social factors on these relationships. Across three independent samples of adults, we assessed resilience factors, autism-related quantitative traits, anxiety symptoms, and depression symptoms during the COVID-19 pandemic. One sample (recruited via the Autism Spectrum Program of Excellence, n = 201) was enriched for autism traits while the other two (recruited via Amazon Mechanical Turk, n = 624 and Facebook, n = 929) drew from the general population. We found resilience factors and quantitative autism-related traits to be inversely related, regardless of the resilience measure used. Additionally, we found that resilience factors moderate the relationship between autism-related quantitative traits and depression symptoms such that resilience appears to be protective. Across the neurodiversity spectrum, resilience factors may be targets to improve mental health outcomes. This approach may be especially important during the ongoing COVID-19 pandemic and in its aftermath.

The relationship between autism spectrum and sleep-wake traits

Autistic children and adults often have sleep disturbances, which may affect their and their family's quality of life. Yet, the relationship between sleep-wake patterns and autism spectrum traits is understudied. Identifying such relationships could lead to future research elucidating common mechanistic underpinnings. Thus, we aimed to determine whether sleep-wake patterns, specifically related to sleep, physical activity, and the daily sleep-wake rhythm (i.e., circadian rhythm), are associated with autism spectrum-related traits. Accelerometer-derived sleep-wake parameters were estimated in individuals with autistic spectrum traits and their family members (N = 267). We evaluated autism spectrum traits using the Social Responsiveness Scale (SRS) to assess the presence and severity of social impairment and the Behavior Rating Inventory of Executive Function (BRIEF) to assess executive function. The linear multivariate regression analysis (using SOLAR-Eclipse) showed that in adults, increased core autism spectrum traits and executive dysfunction were associated with disruption of several sleep-wake parameters, particularly related to the daily sleep-wake rhythm, and that executive dysfunction was associated with disrupted sleep quality and level of physical activity. We highlight the interplay between daytime function and disrupted sleep-wake patterns, specifically related to the daily sleep-wake rhythm, that could guide future research into common mechanisms.

Structural and Functional Differences in Skin of Colour

The term, Skin of Colour (SOC), refers to individuals of African, Latinx, Asian, Native Hawaiian, Pacific Islander and Indigenous descent. These individuals typically have darker skin tones as compared to white individuals and they often present with unique disorders of the skin or with common disorders that have a unique appearance. Certain skin conditions commonly associated with SOC patients, in contrast to individuals with lighter skin tones, are explained by structural and functional differences between this population and the white population. Variations in functional differences between these two groups are dependent on structural differences in melanosomes, stratum corneum, epidermis and dermis. Understanding the structural distinctions between white populations and SOC populations, will provide insight into common disorders in skin of colour patients, including hyperpigmentation, hypopigmentation, dry skin, scaliness, xerosis, sensitive skin and keloids. Furthermore, understanding structural and functional skin difference will encourage more research regarding etiology of disease and therapeutic interventions.

Heritability of quantitative autism spectrum traits in adults: A family-based study

Autism spectrum disorder (ASD) comprises a multi-dimensional set of quantitative behavioral traits expressed along a continuum in autistic and neurotypical individuals. ASD diagnosis-a dichotomous trait-is known to be highly heritable and has been used as the phenotype for most ASD genetic studies. But less is known about the heritability of autism spectrum quantitative traits, especially in adults, an important prerequisite for gene discovery. We sought to measure the heritability of many autism-relevant quantitative traits in adults high in autism spectrum traits and their extended family members. Among adults high in autism spectrum traits (n = 158) and their extended family members (n = 245), we calculated univariate and bivariate heritability estimates for 19 autism spectrum traits across several behavioral domains. We found nearly all tested autism spectrum quantitative traits to be significantly heritable (h²  = 0.24-0.79), including overall ASD traits, restricted repetitive behaviors, broader autism phenotype traits, social anxiety, and executive functioning. The degree of shared heritability varied based on method and specificity of the assessment measure. We found high shared heritability for the self-report measures and for most of the informant-report measures, with little shared heritability among performance-based cognition tasks. These findings suggest that many autism spectrum quantitative traits would be good, feasible candidates for future genetics studies, allowing for an increase in the power of autism gene discovery. Our findings suggest that the degree of shared heritability between traits depends on the assessment method (self-report vs. informant-report vs. performance-based tasks), as well as trait-specificity. LAY SUMMARY: We found that the scores from questionnaires and tasks measuring different types of behaviors and abilities related to autism spectrum disorder (ASD) were heritable (strongly influenced by gene variants passed down through a family) among autistic adults and their family members. These findings mean that these scores can be used in future studies interested in identifying specific genes and gene variants that are associated with different behaviors and abilities related with ASD.

Test-retest reliability of the two-point discrimination test on the sole of the foot in people with multiple sclerosis

BACKGROUND

Two-point discrimination (TPD) is an assessment of tactile acuity. People with multiple sclerosis (MS) can have reduced foot sole tactile acuity, which has been linked to impaired balance.

OBJECTIVE

To quantify the test-retest reliability of TPD on the sole of the foot in people with MS.

APPROACH

41 participants (32 females), with mean (SD) age of 60 (9) years, and Expanded Disability Status Scale of <7.5, had their TPD measured at the head of the first metatarsal and the heel on two occasions, 2-14 d apart. Mean systematic change, within-subjects SD, limits of agreement (LOA), coefficient of variation and the intraclass correlation coefficient (ICC) were quantified as point estimates (95% CI).

MAIN RESULTS

Systematic learning effects were evident. The within-subjects SD at the metatarsal and the heel was 6.7 mm (5.5-8.6) and 8.3 mm (6.7-10.8), and the LOAs were 18.6 mm (15.2-24.) and 23.7 mm (18.7-30.1), respectively. ICCs for metatarsal and heel was 0.87 (0.76-0.93) and 0.90 (0.80-0.95), respectively, but these were likely inflated by sample heterogeneity.

SIGNIFICANCE

In people with MS, TPD on the sole of the foot has an adequate test-retest reliability for research purposes, but there is substantial measurement variability for individual patients.

Implicit and Explicit Attitudes Toward Autistic Adults

Background

Research examining attitudes toward autistic adults has relied on explicit self-report measures, which may be susceptible to socially desirable responding. Because implicit attitudes predict behavioral rejection, understanding both implicit and explicit attitudes toward autistic adults is important. Furthermore, previous research has almost exclusively examined attitudes toward autistic children and has not investigated attitudes toward autistic adults who may also experience prejudice from their peers.

Methods

We created an implicit association test (IAT) to examine implicit attitudes toward autistic adults. In Study 1, we examined 94 neurotypical adults' (mean [M]_age = 31.37 years) implicit attitudes and explicit attitudes toward autistic adults as well as autistic behaviors. In Study 2 (n = 137; M _age = 33.43 years), we assessed the same variables using an IAT with descriptive rather than stereotypical words.

Results

Participants from both studies demonstrated negative implicit attitudes but positive explicit attitudes toward autistic adults. In Study 2, analyses examining self-reported traits related to autism revealed that more autistic behaviors were associated with less implicit bias.

Conclusions

These findings may help explain why autistic adults report discrimination from their peers. The results suggest that there may be benefits in modifying interventions that reduce implicit bias toward other marginalized groups for use with implicit bias against autistic adults.

Lay summary

Why was this study done?: The goal of this study was to understand how neurotypical adults in the United States feel and think about autistic adults. Negative attitudes can lead to discrimination against autistic adults or to harmful interactions between autistic and neurotypical adults. Although research has previously examined the attitudes that neurotypical adults have toward autistic adults, most of this work has directly asked people about their attitudes, assessing their explicit, or conscious, attitudes. Neurotypical adults, however, may not be able or willing to admit that they have negative attitudes toward autistic adults. Therefore, it is important to evaluate implicit attitudes, which are underlying attitudes at the unconscious level of awareness.What was the purpose of this study?: This study investigated the implicit and explicit attitudes that neurotypical adults in the general U.S. population have about autistic adults. Assessing both kinds of attitudes is important because each type of attitude predicts different sorts of behaviors toward and judgments of individuals.What did the researchers do?: We conducted this study online using a crowdsourcing method of data collection (Amazon's Mechanical Turk) that gave us access to adults throughout the United States. We developed and administered a reaction-time task to examine implicit attitudes toward autistic adults. In this task, participants rapidly categorized words associated with autism and words not associated with autism as being "good" or "bad." We assessed explicit attitudes with questions about people's knowledge of autism and their liking for autistic adults. Study 1 measured 94 neurotypical adults' (average age = 31.37 years) implicit and explicit attitudes toward autistic adults; Study 2 measured 137 neurotypical adults' (average age = 33.43 years) implicit and explicit attitudes. Whereas Study 1's implicit task used words associated with stereotypes about autistic adults (e.g., extraverted, independent), Study 2 used nonstereotypical words associated with autism (e.g., autistic, spectrum).What were the results of the studies?: Participants in both studies reported positive explicit attitudes but negative implicit attitudes toward autistic adults. In one study, we also found that neurotypical adults with more autistic traits themselves had more positive implicit attitudes toward autistic adults.What do these findings add to what was already known?: Although previous research examined neurotypical adults' explicit attitudes toward autistic adults, the current study demonstrated that neurotypical adults hold negative implicit attitudes toward autistic adults. These findings may help explain why autistic adults experience discrimination from neurotypical adults. Furthermore, our findings suggest that having more autistic traits can lead to a better understanding of the behaviors associated with autism.What are the potential weaknesses in the study?: Limitations of the study were that we collected the data online rather than in person and we only included neurotypical adults as participants.How will these findings help autistic adults now or in the future?: These results shed light on underlying reasons for the potential negative judgments and discrimination that autistic adults face from neurotypical adults. These findings should encourage policy makers to design and implement training programs to reduce neurotypical adults' negative attitudes toward autistic adults.

0974 Family-Based Study Of Sleep In Autism Spectrum Disorder Without Intellectual Disability

Introduction

Sleep problems are a common concern in children with autism spectrum disorder (ASD) that can persist into adulthood. This study aims to further explore sleep in ASD without intellectual disability (ASD w/o ID).

Methods

We recruited individuals with ASD w/o ID (probands) and relatives as part of the Autism Spectrum Program of Excellence (ASPE) at the University of Pennsylvania. Actimetry data were collected via a wrist-worn tri-axial accelerometer for 21 days. Data from 212 participants were considered. We analyzed sleep data using the algorithms GGIR, ChronoSapiens, and PennZzz. The sleep traits of proband and sibling pairs were compared using paired t-test or Wilcoxon signed-rank test. We used the Social Responsiveness Scale, Second Edition (SRS-2) to assess social impairment and restricted/repetitive traits. We compared SRS-2 scores to sleep traits using partial Spearman or Pearson correlations adjusting for age (171 participants).

Results

Probands demonstrated later sleep onset (p = 0.03), decreased M10 average (10-hour period of highest activity/day; p = 0.006), decreased relative amplitude (measure of rest-activity rhythm; p&lt;0.001), and decreased total daytime activity (p = 0.005) compared to siblings. Regarding social function and restricted/repetitive traits, adult males showed an inverse correlation between SRS-2 total score and sleep efficiency (r = -0.2, p= 0.04) and a positive correlation between SRS-2 total score and intradaily variability (r = 0.3, p = 0.02). Adult females showed an inverse correlation between SRS-2 total score and M10 average (r = -0.3, p = 0.02) and between SRS-2 total score and relative amplitude (self-report r = -0.4, p = 0.001; informant r = -0.3, p = 0.005).

Conclusion

This study focuses on the analysis of sleep traits in ASD including the relationship between social function and sleep. Thus far, the most robust findings are decreased daytime activity and relative amplitude in individuals with ASD w/o ID compared to siblings. We have also shown that ASD social impairment may be related to sleep dysfunction.

Support

NIH T32HL07713, anonymous donor, and the Institute for Translational Medicine and Therapeutics of the Perelman School of Medicine at the University of Pennsylvania.

Preparing for the MFAEM examination

The MFAEM may take over as the primary membership examination for progression to higher professional training in Emergency Medicine. As a relatively young examination it still suffers from a lack of associated study material and a formal syllabus. The emergence of a specific membership examination such as MFAEM represents the growth in stature of A&E as a speciality in its own right. As the examination becomes more popular and growing numbers of doctors apply there will be a similar expansion of study material and available resources. MRCSEd(A&E) remains a solid alternative and eligibility for this examination is similar to MFAEM part B. However, success at a relevant part one is required before sitting this. The MFAEM part A is more balanced and relevant primary examination for A&E trainees but if one is interested in dual accreditation or has a specific interest in another speciality then sitting the MRCP, MRCS or FRCA may be more appropriate before approaching the MFAEM part B or MRCSEd(A&E).

Infection with an avirulent phoP mutant of Neisseria meningitidis confers broad cross-reactive immunity

Successful vaccines against serogroup A and C meningococcal strains have been developed, but current serogroup B vaccines provide protection against only a limited range of strains. The ideal meningococcal vaccine would provide cross-reactive immunity against the variety of strains that may be encountered in any community, but it is unclear whether the meningococcus possesses immune targets that have the necessary level of cross-reactivity. We have generated a phoP mutant of the meningococcus by allele exchange. PhoP is a component of a two-component regulatory system which in other bacteria is an important regulator of virulence gene expression. Inactivation of the PhoP-PhoQ system in Salmonella leads to avirulence, and phoP mutants have been shown to confer protection against virulent challenge. These mutants have been examined as potential live attenuated vaccines. We here show that a phoP mutant of the meningococcus is avirulent in a mouse model of infection. Moreover, infection of mice with the phoP mutant stimulated a bactericidal immune response that not only killed the infecting strain but also showed cross-reactive bactericidal activity against a range of strains with different serogroup, serotype, and serosubtyping antigens. Sera from the mutant-infected mice contained immunoglobulin G that bound to the surface of a range of meningococcal strains and mediated opsonophagocytosis of meningococci by human phagocytic cells. The meningococcal phoP mutant is thus a candidate live, attenuated vaccine strain and may also be used to identify cross-reactive protective antigens in the meningococcus.

Hypoparathyroidism and 22q11 deletion syndrome

AIMS

To investigate a population of individuals with 22q11 deletion syndrome for hypocalcaemia.

METHODS

A detailed clinical history enquiring into symptoms of hypocalcaemia and blood sampling to assess for hypocalcaemia and hypoparathyroidism, of patients outside the neonatal period known to have the 22q11 microdeletion from fluorescent in situ hybridisation studies was taken.

RESULTS

Sixty one individuals were identified, of whom 23 were untraceable and one was unable to give informed consent. Biochemical investigations were performed on 27 subjects. Ten subjects had review of notes only. Four subjects had previously identified hypoparathyroidism. A new case of hypoparathyroidism was identified. Three subjects had borderline hypocalcaemia.

DISCUSSION

In this population of patients with 22q11 deletion syndrome, 13% of the total or 30% of those biochemically assessed had evidence of reduced serum calcium concentrations. It is likely that 13-30% of patients with 22q11 deletion syndrome have possible hypoparathyroidism outside the neonatal period. Reported symptoms of hypocalcaemia did not correlate with biochemical evidence of persisting hypocalcaemia. We have shown that previously undiagnosed asymptomatic hypoparathyroidism occurs in patients with 22q11 deletion syndrome and conclude that screening of this population should be considered.

Prion protein fragment 106-126 potentiates catecholamine secretion from PC-12 cells

The toxic actions of scrapie prion protein (PrP(sc)) are poorly understood. We investigated the ability of the toxic PrP(sc) fragment 106-126 to interfere with evoked catecholamine secretion from PC-12 cells. Prion protein fragment 106-126 (PrP106-126) caused a time- and concentration-dependent augmentation of exocytosis due to the emergence of a Ca(2+) influx pathway resistant to Cd(2+) but sensitive to other inorganic cations. In control cells, secretion was dependent on Ca(2+) influx through L- and N-type Ca(2+) channels, but after exposure to PrP106-126, secretion was unaffected by N-type channel blockade. Instead, selective L-type channel blockade was as effective as Cd(2+) in suppressing secretion. Patch-clamp recordings revealed no change in total Ca(2+) current density in PrP106-126-treated cells or in the contribution to total current of L-type channels, but a small Cd(2+)-resistant current was found only in PrP106-126-treated cells. Thus PrP106-126 augments secretion by inducing a Cd(2+)-resistant Ca(2+) influx pathway and alters coupling of native Ca(2+) channels to exocytosis. These effects are likely contributory factors in the toxic cellular actions of PrP(sc).

Malignant melanoma in African Americans

Although rare, malignant melanoma (MM) is a real and serious risk for African Americans. African Americans have a proportionately higher incidence of acral melanoma, both the acral lentiginous melanoma (ALM) histologic subtype and subungual melanoma (SM). MM is more likely to be diagnosed at a later stage in African Americans and carries a worse prognosis. Given these facts, the relatively simple and inexpensive primary and secondary preventions for MM should be standard, particularly in the African American patient.

Differential coupling of voltage-gated Ca(2+) channels to catecholamine secretion from separate PC12 cell batches

Amperometric recordings were employed to investigate the coupling of Ca(2+) channels to catecholamine secretion in two batches of pheochromocytoma (PC12) cells. In 'new' (freshly obtained) cells (PC12n cells), secretion was dependent on Ca(2+) influx through L-type and N-type Ca(2+) channels. By contrast, in 'aged' cells (maintained in liquid nitrogen for 6-8 years; PC12a cells), secretion was mostly dependent on Ca(2+) influx through N-type channels. Patch clamp recordings revealed that L-type channels accounted for only ca. 26% of total whole-cell current in PC12a cells (determined by blockade caused by 2 microM nifedipine). In contrast, nifedipine suppressed currents by ca. 59% in PC12n cells. Thus important differences in fundamental physiological properties can be observed in PC12 cell batches even when obtained from the same source and maintained under identical conditions.

Three distinct Ca(2+) influx pathways couple acetylcholine receptor activation to catecholamine secretion from PC12 cells

Amperometry and microfluorimetry were employed to investigate the Ca(2+)-dependence of catecholamine release induced from PC12 cells by cholinergic agonists. Nicotine-evoked exocytosis was entirely dependent on extracellular Ca(2+) but was only partly blocked by Cd(2+), a nonselective blocker of voltage-gated Ca(2+) channels. Secretion and rises of [Ca(2+)](i) observed in response to nicotine could be almost completely blocked by methyllycaconitine and alpha-bungarotoxin, indicating that such release was mediated by receptors composed of alpha7 nicotinic acetylcholine receptor subunits. Secretion and [Ca(2+)](i) rises could also be fully blocked by co-application of Cd(2+) and Zn(2+). Release evoked by muscarine was also fully dependent on extracellular Ca(2+). Muscarinic receptor activation stimulated release of Ca(2+) from a caffeine-sensitive intracellular store, and release from this store induced capacitative Ca(2+) entry that could be blocked by La(3+) and Zn(2+). This Ca(2+) entry pathway mediated all secretion evoked by muscarine. Thus, activation of acetylcholine receptors stimulated rises of [Ca(2+)](i) and exocytosis via Ca(2+) influx through voltage-gated Ca(2+) channels, alpha7 subunit-containing nicotinic acetylcholine receptors, and channels underlying capacitative Ca(2+) entry.

Protein kinase C evokes quantal catecholamine release from PC12 cells via activation of L-type Ca2+ channels

Application of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) to PC12 cells under resting conditions evoked quantal catecholamine secretion, as detected amperometrically. This effect was not mimicked by 4alpha-phorbol-12,13-didecanoate, another phorbol ester, which is inactive with respect to protein kinase C activation, and was prevented by the protein kinase C inhibitor bisindolylmaleimide. TPA also caused a rise of [Ca(2+)](i) in Fura-2-loaded PC12 cells, and again this was not mimicked by 4alpha-phorbol-12,13-didecanoate and could be blocked by bisindolylmaleimide. TPA-evoked secretion was entirely dependent on extracellular Ca(2+) and was fully abolished by nifedipine, as were TPA-induced rises of [Ca(2+)](i). Resting membrane potential, monitored using perforated patch recordings, was unaffected by TPA. However, a small (6-8 mV) hyperpolarizing shift in the voltage dependence of Ca(2+) channel currents (determined using whole-cell patch clamp recordings) was induced by TPA, and this could be fully prevented by nifedipine. In contrast to results with depolarizing stimuli, which evoke exocytosis because of Ca(2+) influx through N-type channels in these cells, the present results indicate that protein kinase C activation leads directly to quantal catecholamine secretion in the absence of depolarizing stimuli via a selective shift in the activation of L-type Ca(2+) channels.

Mitochondrial inhibitors evoke catecholamine release from pheochromocytoma cells

Quantal catecholamine secretion evoked from individual pheochromocytoma (PC12) cells by exposure to mitochondrial inhibitors and uncouplers was monitored in real time using amperometry. Cyanide (0.05-5 mM) caused a concentration-dependent increase in the frequency of amperometric events. This secretory response was abolished by removal of extracellular Ca(2+) and by the application of Cd(2+) (200 microM), a nonselective blocker of voltage-gated Ca(2+) channels. Secretion was also inhibited by ca. 75% following pretreatment of cells with omega-conotoxin GVIA to inhibit N-type Ca(2+) channels selectively. Secretion was also detected when cells were exposed to rotenone (10 microM), dinitrophenol (250 microM) and p-trifluoromethoxyphenyl hydrazone (1 microM) and, as for cyanide, these secretory responses were abolished by removal of extracellular Ca(2+) or application of 200 microM Cd(2+). These results indicate that, like hypoxia, mitochondrial inhibitors and uncouplers evoke catecholamine secretion from PC12 cells which is wholly dependent on Ca(2+) influx through voltage-gated Ca(2+) channels.

Partial Wetting in Capillary Liquid Absorption by Limestones

We report measurements of the capillary absorption (imbibition) of water, n-heptane, n-decane, n-dodecane, methanol, ethanol, propan-2-ol, and ethanol-water mixtures into a number of dry calcitic limestones. The data are analyzed on the basis of unsaturated flow theory to give values of sorptivity S for water and for each organic liquid at different temperatures. The results show that for the organic liquids S varies as (surface tension/viscosity)(1/2) but that for the water S is anomalously low, indicating partial wetting. The wettability of these limestones is discussed in relation to natural contamination of the pore surface. Copyright 2000 Academic Press.

In vivo production of type 1 cytokines in healthy sickle cell disease patients

Interleukins (IL)-1, 2, 12, and interferon (IFN)-gamma, along with soluble IL-2 receptor (sIL-2R) were measured from sera obtained from healthy sickle cell disease (SCD) patients and comparable healthy control subjects. The cytokines were assessed by enzyme-linked immunosorbent assay (ELISA) in 60 SCD patients and 58 controls. No significant detectable levels of IL-1 or IL-12 were found in the sera of either group of patients. Significantly elevated levels of IFN-gamma were measured in 20 (33%) of 60 SCD patients and 21 (36%) of 58 controls. A large subset of 18 (41%) of 43 healthy controls and a smaller subset of 12 (21%) of 58 SCD demonstrated detectable levels of IL-2. The sIL-2R levels of the SCD group (4465 +/- 552 pg/mL) were significantly higher (P < .0001) than that of controls (3473 +/- 411 pg/mL). The results revealed comparable circulating levels of all type 1 cytokines in both healthy SCD and normal control subjects, with the exception of in vivo sIL-2R production. Elevated serum levels of both IL-6 and tumor necrosis factor (TNF)-alpha have been reported previously in a significant percentage of SCD steady-state subjects. These two cytokines are known to increase sIL-2R expression and may help explain the difference between the patient populations. Immune activation markers such as sIL-2R are produced by cells that mediate host responses to infection or inflammatory stimuli. The implication of higher levels of sIL-2R in SCD is not clear, but chronic parvovirus B19 infection, chronic polyclonal activation of B cells or defective regulation of antibodies are possible explanations for the elevated levels in SCD.

Hypoxic enhancement of quantal catecholamine secretion. Evidence for the involvement of amyloid beta-peptides

Prolonged exposure to hypoxia (10% O(2)) enhanced quantal catecholamine release evoked from O(2)-sensing pheochromocytoma (PC12) cells, as monitored using single-cell amperometric recordings. The enhancement of exocytosis was apparent after 12 h of hypoxia and was maximal at 24 h. Elevated levels of secretion were due to the emergence of a Ca(2+) influx pathway that persisted during complete blockade of known voltage-gated Ca(2+) channels. Secretion triggered by this Ca(2+) influx was severely reduced by known inhibitors of Alzheimer's amyloid beta-peptides (AbetaPs), including an N terminus-directed monoclonal antibody. The enhancing effect on secretion of chronic hypoxia was mimicked closely by direct application of AbetaP to cells under normoxic conditions, although the effects of AbetaP were more rapid at onset, being maximal after only 6 h. The present results suggest that prolonged hypoxia can induce formation of Ca(2+)-permeable AbetaP channels and that such induction can lead directly to excessive neurosecretion. This is a potential contributory factor to AbetaP pathophysiology following cerebral ischemia.

Acid-evoked quantal catecholamine secretion from rat phaeochromocytoma cells and its interaction with hypoxia-evoked secretion

1. Amperometric recordings using polarized carbon fibre microelectrodes were used to detect exocytosis of catecholamines from rat phaeochromocytoma (PC12) cells in response to a reduction in pHo. 2. Exocytosis was detected at pHo levels of between 7.2 and 6.8. This was probably due to intracellular acidification, since acid-evoked secretion was enhanced by the Na+-H+ exchange blocker ethylisopropylamiloride (30 microM), and was mimicked by sodium propionate (10 mM), which causes selective intracellular acidosis. 3. Acid-evoked exocytosis was abolished by removal of Ca2+o or application of 200 microM Cd2+. It was unaffected by nifedipine, but significantly reduced by either omega-conotoxin GVIA (1 microM) or omega-agatoxin GIVA (200 nM). The two toxins applied together almost completely abolished (> 97 %) acid-evoked secretion. 4. Hypoxia-evoked catecholamine release was potentiated under acidic conditions and suppressed under alkaline conditions in a manner which indicated a greater than additive interaction of these two stimuli. 5. Our results indicate that, like carotid body arterial chemoreceptors, PC12 cells represent model chemoreceptor cells for both hypoxia and acidity and that the release of catecholamines in response to these physiological stimuli is dependent on Ca2+ influx through voltage-gated N- and P/Q-type Ca2+ channels.

Analysis of a translational enhancer present within the 5'-terminal sequence of the genomic RNA of potato virus S

When present as a transcript leader the 5' untranslated sequence from the potato virus S genomic RNA molecule enhances translation of a downstream open reading frame both in vitro and in vivo. Translational enhancement was 30-fold in rabbit reticulocyte lysate and 15 fold in wheat germ above translation from a transcript with a synthetic leader. Transient expression experiments using tobacco protoplasts and particle bombardment of leaf tissue resulted in enhancement of fourteen and five-fold, respectively, above translation with a synthetic leader. In stably transformed plants the PVS 5'UTR enhanced translation yield ca. 5-fold compared with a synthetic 5'UTR.

Store-operated Ca2+ influx and voltage-gated Ca2+ channels coupled to exocytosis in pheochromocytoma (PC12) cells

Microamperometry was used to monitor quantal catecholamine release from individual PC12 cells in response to raised extracellular K+ and caffeine. K+-evoked exocytosis was entirely dependent on Ca2+ influx through voltage-gated Ca2+ channels, and of the subtypes of such channels present in these cells, influx through N-type was primarily responsible for triggering exocytosis. L-type channels played a minor role in mediating K+-evoked secretion, whereas P/Q-type channels did not appear to be involved in secretion at all. Caffeine also evoked catecholamine release from PC12 cells, but only in the presence of extracellular Ca2+. Application of caffeine in Ca2+-free solutions evoked large, transient rises of [Ca2+]i, but did not trigger exocytosis. When Ca2+ was restored to the extracellular solution (in the absence of caffeine), store-operated Ca2+ influx was observed, which evoked exocytosis. The amount of secretion evoked by this influx pathway was far greater than release triggered by influx through L-type Ca2+ channels, but less than that caused by Ca2+ influx through N-type channels. Our results indicate that exocytosis may be regulated even in excitable cells by Ca2+ influx through pathways other than voltage-gated Ca2+ channels.

Potentiation of quantal catecholamine secretion by glibenclamide: evidence for a novel role of sulphonylurea receptors in regulating the Ca(2+) sensitivity of exocytosis

Electrochemical detection of quantal catecholamine release from PC-12 cells revealed that glibenclamide, an inhibitor of ATP-sensitive K(+) channels, potentiated Ca(2+)-dependent exocytosis evoked by raised extracellular [K(+)] and by exposure of cells to caffeine. Glibenclamide was without effect on voltage-gated Ca(2+) currents, membrane potential, or rises of [Ca(2+)](i) evoked by either raised extracellular [K(+)] or caffeine. The dependence of K(+)-evoked secretion on extracellular Ca(2+) was shifted leftward in the presence of glibenclamide, with a small increase in the plateau level of release, suggesting that glibenclamide primarily increased the Ca(2+) sensitivity of the exocytotic apparatus. Enhancement of secretion by glibenclamide was reversed by pinacidil and cromakalim, indicating that the effects of glibenclamide were mediated via an action on a sulfonylurea receptor. These results demonstrate that sulfonylurea receptors can modulate Ca(2+)-dependent exocytosis via a mechanism downstream of Ca(2+) influx or mobilization.

Cosmetic problems in skin of color

Practitioners are confronted with a myriad of cutaneous diseases affecting skin of color. Skin of color, which encompasses the pigmented skin of those of African American, Asian and Hispanic descent is susceptible to several unique and cosmetically disfiguring problems. Acne vulgaris, pseudofolliculitis barbae, postinflammatory hyperpigmentation and photoaging are diseases which commonly necessitate visits to the dermatologist and are of major cosmetic concern for those with skin of color. Effective treatments are needed to quickly resolve the inflammatory lesions of acne and pseudofolliculitis. The number of agents available for the treatment of postinflammatory hyperpigmentation is limited, and some agents are minimally effective. In addition to more effective therapeutic agents, development of enhanced camouflaging techniques are also necessary. Finally, sunscreens which provide more complete protection for skin of color are needed to address the issue of both photoaging and hyperpigmentation. We look to the cosmetic industry to develop new products and to improve currently existing products to address the cosmetic concerns of skin of color.

Chronic hypoxia enhances the secretory response of rat phaeochromocytoma cells to acute hypoxia

1. Amperometric recordings were made from individual phaeochromocytoma (PC12) cells using carbon fibre microelectrodes to investigate the effects of chronic hypoxia (10% O2) on the secretory responses evoked by acute hypoxia. 2. Exposure to chronic hypoxia for 21-26 h increased the frequency of exocytotic events evoked in response to acute hypoxia (PO2 ca 10-60 mmHg). 3. Chronic hypoxia increased the value of Q1/3, determined by the integration of amperometric events, indicating an increase in quantal size: this reflects either an increase in vesicular dimensions or vesicular catecholamine concentration. 4. Exocytotic frequency evoked by bath application of tetraethylammonium (1-10 mM) was significantly enhanced following chronic hypoxia. 5. In both control and chronically hypoxic PC12 cells, exocytosis in response to acute hypoxia was completely abolished in Ca2+-free solutions. Cd2+ (200 microM) completely inhibited exocytosis from control cells, but left a significant residual release in chronically hypoxic PC12 cells. 6. The Cd2+-resistant release evoked by acute hypoxia in chronically hypoxic PC12 cells was inhibited by inorganic ions (0.01-10 mM) in a potency order of La3+ > Gd3+ > Zn2+. Ni2+ (10 mM) was without effect. 7. Our results suggest that chronic hypoxia enhances the secretory response of PC12 cells in part by increasing the depolarization mediated by an oxygen-sensitive K+ channel. In addition, acute hypoxia activates a Cd2+-resistant Ca2+ influx pathway in chronically hypoxic PC12 cells.

Hypoxia evokes catecholamine secretion from rat pheochromocytoma PC-12 cells

We have monitored exocytosis of catecholamines from individual PC-12 cells by amperometry using carbon fiber microelectrodes in order to investigate possible secretory responses to acute hypoxia. In normoxia, no secretion was detected from cells perfused with a solution containing 5 mM K+. However, when [K+] was raised (10-100 mM), exocytotic events were observed. Hypoxia (PO2 11 mmHg) stimulated secretion from PC-12 cells, and in hypoxic conditions exocytosis was greater at each [K+] studied as compared with normoxia. Hypoxia-evoked secretion was abolished in Ca2+ free solutions containing 1 mM EGTA and by the non-specific Ca2+ channel blocker, Cd2+ (200 microM). Secretion was also largely inhibited by omega-conotoxin GVIA (1 microM). Exocytosis was also observed in normoxia when cells were exposed to tetraethylammonium (1-10 mM), but not 4-aminopyridine (3 mM). Our findings indicate that hypoxia evokes exocytosis via depolarization arising from inhibition of a TEA-sensitive K+ conductance, leading to Ca2+ influx primarily via N-type Ca2+ channels.

Comparisons of three probability formulae for parentage exclusion

Three general formulae calibrate the average capability of marker systems to dispute falsely reported pedigree records in uniparous species. The most familiar exclusion formula applies to paternity, although the same formula applies equally to maternity. Another formula faults the relationship of a single offspring with its putative parent; for example, where the genotype of the other parent is not available. The remaining formulae excludes both of the falsely recorded parents of a substituted offspring. Simplified forms of the three general formulae facilitate the calculation of maximal average exclusion values over a range of hypothetical markers. Allele frequency data on eight marker systems in horses provide practical examples. The exclusion values of the three formulae are compared.

Type 2 cytokine serum levels in healthy sickle cell disease patients

Sickle cell disease (SCD) is characterized by significant morbidity and early mortality. Children with this hemoglobinopathy exhibit many of the manifestations associated with immunodeficiency disorders. Serum was obtained from 56 healthy SCD subjects and 45 normal healthy controls. Type 2 cytokines interleukin (IL)-4, IL-6, and IL-10 serum levels were measured. Concentrations were determined by reference to a standard curve, and results were expressed in pg/mL. Results revealed significant levels of IL-4 in 6 (13%) of 45 SCD patients compared with 1 (2%) of 45 controls. Increased levels of IL-6 were present in 35 (78%) of 45 SCD patients and 12 (41%) of 29 controls. Elevated levels of IL-10 were detectable in 13 (41%) of 42 SCD patients and 1 (4%) of 25 controls. High circulating levels of type 2 cytokines may suppress both humoral and cell-mediated immune functions in SCD, with resultant increased morbidity.

In vitro lymphocyte blastogenic responses and cytokine production in sickle cell disease patients with acute pneumonia

BACKGROUND

Pulmonary infections continue to be a major cause of morbidity and mortality in patients with sickle cell disease (SCD).

METHODS

In this study cell-mediated immunity in vitro was evaluated in 62 SCD patients (62 steady state and 16 with acute pneumonia) and compared with 44 normal controls (30 healthy and 14 with acute pneumonia). Lymphocyte blastogenic responses to phytohemagglutinin, tetanus toxoid and Candida albicans antigen were assessed in all subjects. In addition production of tumor necrosis factor, alpha- and gamma-interferon (IFN) were assayed.

RESULTS

The results revealed comparable blastogenic responses to all three stimuli in all subjects except SCD patients with pneumonia. This group showed poor responses to all stimuli. The mean counts per minute were decreased 65 to 90% when compared with the other patients. Cytokine production of IFN-alpha and TNF was equivalent in all subjects. Conversely IFN-gamma production in both SCD groups, steady state (35 +/- 6 U/ml) and SCD with pneumonia (14 +/- 6 U/ml), was significantly decreased when compared with those in normal healthy controls (65 +/- 14 U/ml) and with pneumonia (48 +/- 17 U/ml). On analysis of individual titers 15 of 62 (24%) steady state and 10 of 16 (63%) SCD patients with pneumonia were deficient in IFN-gamma production in vitro.

CONCLUSIONS

Acute pulmonary infections seem to have a profound effect on cell-mediated immunity in SCD. IFN-gamma deficiency, along with quantitative and qualitative T cell abnormalities, may represent significant factors to explain the frequent and severe infections seen in SCD.

Serum interleukin-6 levels in the steady state of sickle cell disease

In patients with childhood sickle cell disease (SCD) serum interleukin-6 (IL-6) levels were measured during the steady (healthy) state of disease. The corresponding measurements were made in comparable healthy normal controls. Serum IL-6 levels were assessed via ELISA in 27 SCD patients and 19 controls. Results revealed significantly higher circulating levels of IL-6 in the SCD patients (60 +/- 7 pg/ml) compared with the healthy controls (12 +/- 5 pg/ml). IL-6 is a multifunctional cytokine that plays a central role in host defense mechanisms. The impact of high circulating levels of IL-6 may be deleterious to humoral and cell-mediated immune functions in SCD, with resultant heightened risk for morbidity.

The 4-hydroxy-2-oxovalerate aldolase and acetaldehyde dehydrogenase (acylating) encoded by the nahM and nahO genes of the naphthalene catabolic plasmid pWW60-22 provide further evidence of conservation of meta-cleavage pathway gene sequences

We report the complete nucleotide sequence and over-expression of the nahOM genes for the acetaldehyde dehydrogenase (acylating) and the 4-hydroxy-2-oxovalerate aldolase from the meta pathway operon of the naphthalene catabolic plasmid pWW60-22 from Pseudomonas sp. NCIMB9816. Additional partial sequence analysis of adjacent DNA shows the gene order within the operon to be nahNLOMK, identical to the order found for the isofunctional genes in the meta pathway operons in the toluene/xylene pathway of TOL plasmid pWW0 and the phenol/methylphenol pathway of pVI150. The deduced amino acid sequences of NahO and NahM were significantly homologous to the equivalent enzymes encoded by other Pseudomonas meta pathways, although both were the most divergent in each comparison. The nahOM genes were inserted downstream of the T7 promoter in the expression vector pET3a and similar constructs were also made of the isofunctional regions from pVI150 (dmpFG) and TOL plasmid pDK1 (xyIQK). High expression of all three gene pairs was detected by enzyme assays and by SDS-PAGE.

A novel pathway for the catabolism of 4-nitrotoluene by Pseudomonas

Eleven strains of Pseudomonas were isolated by selective enrichment on 4-nitrotoluene (4NT). They all utilized 4NT, 4-nitrobenzyl alcohol (4NBA) or 4-nitrobenzoate (4NBZate) as sole sources of carbon and nitrogen. One strain, TW3, was used for more detailed studies. 4NT-grown cells of TW3 take up O2 when incubated in the presence of 4NBA, 4-nitrobenzaldehyde (4NBZ) and 4NBZate. HPLC analysis of culture supernatants showed that 4NBZ and 4NBZate were formed when 4NT-grown cells wer incubated with 4NBA, whereas only 4NBZate was found when they were incubated with 4NBZ. Two dehydrogenases were detected in extracts of 4NT-grown cells. 4NBA dehydrogenase could be assayed by a dye-linked assay whereas 4NBZ dehydrogenase activity was linked to NAD+ reduction. No nitrite was detected in supernatants of 4NBZate-grown cells incubated with 4NBZate but the nitrogen appeared as ammonium. The only aromatic ring-cleavage dioxygenase that was induced during growth on the nitroaromatics was protocatechuate 3,4-dioxygenase. It is proposed that the pathway for 4NT catabolism proceeds via 4NBA, 4NBZ and 4NBZate and ultimately to protocatechuate with release of the nitro group as ammonium.

Subungual osteochondroma. Diagnosis and management

Osteochondroma, a benign tumor of bone that may penetrate the skin is rarely recognized by the dermatologist. We report two cases of osteochondroma of the distal phalanges with cutaneous penetration, and discuss the clinical, histologic, and radiographic features that allow rapid identification of this lesion. Furthermore, we emphasize the importance of total tumor excision, including adequate treatment of the underlying bone, to prevent recurrence of the lesion.

Quantitation of lysophosphatidylcholine molecular species in rat cardiac tissue

We have developed a rapid and sensitive procedure for isolation and measurement of 1-acyllysophosphatidylcholine (LPC) species in rat myocardial tissue. Tissues were spiked with heptadecanoyl-LPC internal standard and extracted with chloroform/methanol. The chloroform phase was dried, resuspended in chloroform/propan-2-ol (2/1, v/v), and applied to an aminopropyl-bonded phase (Bond Elut) column. Following stepwise elution with several solvent mixtures, the LPC fraction (ethyl acetate/methanol, 4/6, v/v) was separated by HPLC with direct quantitation of palmitoyl-LPC (P-LPC), oleoyl-LPC (O-LPC), and stearoyl-LPC (S-LPC), using an evaporative light scattering mass detector. Calibration curves were generated for each individual LPC species. Recoveries of added [14C]LPC and of heptadecanoyl-LPC internal standard after extraction and chromatography were 85.8 +/- 1.9% (mean +/- SE, N = 10) and 83.4 +/- 1.8% (N = 15), respectively. This assay showed satisfactory sensitivity, reproducibility, and accuracy for measurement of LPC species in rat myocardial tissue. The major molecular species of LPC in rat myocardium were found to be P-LPC and S-LPC, which were two- to sixfold as abundant as O-LPC. In isolated, crystalloid-perfused rat hearts the time of perfusion was found to significantly influence the content of P-LPC (0 min, 252 +/- 10; 15 min, 178 +/- 10, P less than 0.001, compared with 0 min; 40 min, 131 +/- 4, P less than 0.001; and 70 min, 129 +/- 4, P less than 0.001; nmol/g dry weight), but not the content of O-LPC and S-LPC. The method will be useful for studying the participation of LPC species in physiology, pathophysiology, and therapeutics.

Construction and analysis of infectious transcripts synthesized from full-length cDNA clones of both genomic RNAs of pea early browning virus

Full-length cDNA clones of both RNAs of pea early browning virus have been constructed. Synthetic transcripts derived in vitro from these clones are infectious when inoculated onto plants. Electron microscopy revealed the presence of virions in transcript-inoculated plants, and both purified RNA and virions isolated from such plants could be used to infect other plants. Transcripts of RNA1 alone were able to replicate and spread systemically which is a characteristic of members of the tobravirus group of plant viruses.

Cardioprotective effects of the potassium channel opener cromakalim: stereoselectivity and effects on myocardial adenine nucleotides

We determined if the cardioprotective effects of the potassium channel opener cromakalim are stereoselective and if it can preserve adenine nucleotides in ischemic myocardium. We subjected isolated isovolumically beating rat hearts to 25 min of global ischemia and reperfusion with and without pretreatment by cromakalim or its enantiomers. All of these compounds significantly increased preischemic coronary flow with the (3S,4R)-(-)-enantiomer being more potent (EC25 = 0.52 microM) compared to cromakalim (EC25 = 1.04 microM) and the (3R,4S)-(+)-enantiomer (EC25 greater than 100 microM). The (-)-enantiomer was also significantly more potent in reducing ischemic/reperfusion damage compared to cromakalim and its (+)-enantiomer. Reperfusion contractile function was improved significantly and lactate dehydrogenase release was reduced by these compounds. Time to contracture was also increased significantly by the (-)-enantiomer (EC25 = 2.27 microM), cromakalim (EC25 = 4.89 microM) and the (+)-enantiomer (EC25 greater than 100 microM). We determined if cromakalim, in a concentration which does not depress cardiac function (10 microM), can preserve high energy phosphates during ischemia in isolated rat hearts. Cromakalim significantly preserved ATP at 15 to 25 min of ischemia. Adenylate energy charge was also significantly improved by cromakalim at 20 to 25 min into an ischemic episode. Thus, the cardioprotective effects of cromakalim are stereoselective and may be due partly to preservation of myocardial energy reserves. It is significant that cromakalim can preserve adenine nucleotides despite its lack of negative inotropic effects.

Nail cosmetics

Disorders of the nails may be brought about by systemic disease or outside influences. Although many of the products available on the market may be of great benefit in offering palliation of abnormalities of the nail plate, they may also be a source of significant adverse effects. Treatment of nail disorders must be predicated on a well-focused history, physical examination, and proper tissue samples.

Acetylcholinesterase activity in regions of mouse brain following acute and chronic treatment with a benzodiazepine inverse agonist

1. Chronic administration of the benzodiazepine inverse agonist FG 7142 has previously been shown to induce seizure activity in mice. In the present study we have investigated the effects of acute and chronic treatment with FG 7142 in mice on the levels of acetylcholinesterase activity in cortex, hippocampus, midbrain and striatum. We have also investigated the effects of acute and chronic stress in the form of handling (vehicle-injection) on acetylcholinesterase levels. 2. A single dose of FG 7142 produced a marked elevation of total acetylcholinesterase activities in the hippocampus and midbrain when compared with vehicle-injected control levels, but the levels were not different from those in unhandled animals. 3. Acute stress, in the form of vehicle-injection produced decreases in cortical and hippocampal soluble acetylcholinesterase activity but FG 7142 had no effect upon these stress-induced changes. 4. Total cortical and hippocampal acetylcholinesterase activities were increased by 56% and 16% respectively in the chronic FG 7142-treated mice that exhibited seizure activity (compared with vehicle-injected controls). 5. Soluble acetylcholinesterase activity in the midbrain was decreased to 82% of control levels only in animals that had undergone FG 7142-induced kindling. Smaller or no changes in acetylcholinesterase activity in the midbrain were observed in chronically FG 7142-treated animals that exhibited no seizure activity. 6. Mice that did not demonstrate seizure activity in response to chronic FG 7142 treatment showed alterations in the soluble acetylcholinesterase activities of the hippocampus and midbrain. 7. It is concluded that chronic treatment with the benzodiazepine inverse agonist FG 7142 produces alterations in the acetylcholinesterase activities of various brain regions, in a manner related to the kindling that can be produced by this treatment. 8. Chronic mild stress, in the form of repeated handling (vehicle injection), induced changes in brain activity with decreases in total activity occurring in the cortex and hippocampus, and an increase in soluble acetylcholinesterase activity occurring in the midbrain. 9. All these stress-induced changes appeared to be prevented by administration of FG 7142 at the time of the stress. It would appear therefore that FG 7142 can prevent the effects of chronic stress on brain acetylcholinesterase activity.

Projected incidence of cardiovascular disease in male firefighters based on current risk factor prevalence

The projected incidence of cardiovascular disease (CVD) in male firefighters was determined by the prevalence of current CVD risk factors and the use of the Framingham Study general cardiovascular risk profile in a probability sample of firefighters from two municipal fire departments. Hypercholesterolemia (60.9%) and obesity (56.0%) were the most prevalent risk factors. Significant age-related trends were observed for the prevalence of all CVD risk factors, except glucose intolerance (P = .21) and an abnormal resting electrocardiogram (P = .07). The projected incidence of CVD in firefighters did not differ from that of the general male population (relative risk, 1.0; 95% confidence interval, 0.7 to 1.4); similar risk estimates were observed in age-specific analyses. These findings are in accord with previous incidence and mortality studies that used circulatory diseases as an end point. The present method should be viewed primarily as a hypothesis-generating tool because of its limitations in assessing cause and effect.

Pea early browning virus RNA1 encodes four polypeptides including a putative zinc-finger protein

We have determined the complete nucleotide sequence of RNA1 of the tobravirus pea early browning virus [PEBV] from an overlapping series of cDNA clones. The 7073 nucleotide sequence contains four open reading frames [ORFs]. The 5' proximal ORF encodes a 141K polypeptide, and readthrough of the opal [UGA] termination codon of this ORF would lead to the synthesis of a second, 201K polypeptide. Both of these polypeptides have extensive amino acid homology with the putative replicase proteins of tobacco rattle virus [TRV] and tobacco mosaic virus [TMV]. The third ORF encodes a 30K polypeptide which has homology with the TRV 29K and TMV 30K putative cell-to-cell spread proteins. The fourth, 3' proximal ORF encodes a 12K polypeptide which has extensive homology with the TRV 16K protein whose function is unknown. Examination of the amino acid sequences of the 12K and 16K gene products reveals in each the presence of two multiple-cysteine/histidine motifs, a finding which suggests that these proteins might have zinc and/or nucleic acid-binding properties.

Chronic benzodiazepine treatment increases the effects of the inverse agonist FG7142

A schedule of treatment with the benzodiazepine, flurazepam, in mice for 7 days caused a significant enhancement of the convulsive effects of the partial inverse agonist FG7142. Full convulsions were seen with FG7142 after the chronic administration of flurazepam, although this compound does not cause convulsions in normal mice of the strain used. The change appeared to be maximal at 24 hr after the last dose of flurazepam and lasted for up to a week. The chronic treatment with flurazepam caused tolerance to the effects of flurazepam, but the tolerance was of shorter duration than the increase in the effects of FG7142. When the benzodiazepine antagonist, Ro 15-1788, was given with the flurazepam, the incidence of convulsions induced by FG7142 was no longer significant. Repeated administration of midazolam also slightly increased the effects of FG7142. Single doses of flurazepam or midazolam did not significantly alter the effects of FG7142, although some convulsions were seen.

Changes in benzodiazepine/GABA receptor complex function in benzodiazepine-tolerant mice

Mice were given flurazepam, 40 mg k-1, IP, once daily for 7 consecutive days. Twenty-four and forty-eight hours after the last injection measurements were made of the effects on convulsion threshold, body temperature and locomotor activity, of drugs acting on the GABA receptor complex. Significant decreases were seen in the hypothermic and hypomobility effects of progabide at 48 h, but no significant changes were seen in the effects of pentylenetetrazol or pentobarbitone. The actions of picrotoxin in all three types of test and the convulsant action of bicuculline (IP) were significantly decreased at 24 h but not at 48 h. The convulsive, but not the hypothermic, effects of picrotoxin were increased at the 48 h interval. These results may suggest that the chronic benzodiazepine treatment decreased some aspects of GABA receptor function at 48 h after the last dose; however, such an effect probably does not explain the previously reported increases in the effects of inverse agonists following chronic agonist treatment.