Changes in event-related potentials in a three-stimulus auditory oddball task after mild head injury

Previous research has demonstrated changes in event-related potentials in a variety of cognitive tasks after severe closed head injury. We sought to establish if similar changes were present in patients who had sustained only apparently mild head injury (MHI) by recording event-related potentials in a group of 24 mild head injured and 24 control participants during a three-stimulus auditory target detection task. For this "oddball" task participants were required to press a button every time they heard a rare target tone and to ignore rare novel sounds and frequent non-target tones. Neuropsychological test results indicated that the mild head injured group had mild memory and attention impairments. Analysis of behavioural performance on the three-stimulus "oddball" task showed no difference in reaction times or error rates between the two groups. Target condition N2 deflections appeared to be larger in the mild head injured but peak amplitude measures revealed that this effect was not significant. There were no significant differences in the amplitude or latency of the P3b evoked by target stimuli or the P3a evoked by novel stimuli. However, a putative "O-wave" or "reorienting negativity" following the P3a was more negative in the mild head injured group suggesting increased activation of components of the attention network. These findings lend support to the hypothesis that MHI can cause subtle cognitive impairments that are associated with abnormal allocation of attention resources in the context of normal behavioural performance.

Multidimensional family therapy for adolescent drug abuse: results of a randomized clinical trial

Random assignment was made of 182 clinically referred marijuana- and alcohol-abusing adolescents to one of three treatments: multidimensional family therapy (MDFT), adolescent group therapy (AGT), and multifamily educational intervention (MEI). Each treatment represented a different theory base and treatment format. All treatments were based on a manual and were delivered on a once-a-week outpatient basis. The therapists were experienced community clinicians trained to model-specific competence prior to the study and then supervised throughout the clinical trial. A theory-based multimodal assessment strategy measured symptom changes and prosocial functioning at intake, termination, and 6 and 12 months following termination. Results indicate improvement among youths in all three treatments, with MDFT showing superior improvement overall. MDFT participants also demonstrated change at the 1-year follow-up period in the important prosocial factors of school/academic performance and family functioning as measured by behavioral ratings. Results support the efficacy of MDFT, a relatively short-term, multicomponent, multitarget, family-based intervention in significantly reducing adolescent drug abuse and facilitating adaptive and protective developmental processes.

The delusions of Capgras and intermetamorphosis in a patient with right-hemisphere white-matter pathology

Previous neuropsychological studies have demonstrated an association between person misidentification and right-hemisphere dysfunction. In the study reported here, we explore the contribution of facial and visual recognition impairments in a patient with right-hemisphere subcortical white-matter pathology in the frontal and parietal lobes and a diagnosis of vascular cognitive impairment. The patient displayed false recognition of unfamiliar faces and deficient retrieval of key biographic detail for famous faces. These results are discussed in the context of the contribution of deficiencies in the visual system and subcortical white-matter lesions to the development of Capgras delusion.

Variation in melanin content and composition in type V and VI photoexposed and photoprotected human skin: the dominant role of DHI

A combination of techniques, including high-performance liquid chromatography (HPLC), spectrophotometric measurements, and a novel method for quantifying melanosome morphology, were applied to the analysis of melanin content and composition in highly pigmented (Fitzpatrick type V and VI) human skin. We found that total epidermal melanin content is significantly elevated in photoexposed type V and VI skin (approximately 1.6 x), while analysis of individual melanin components suggests that pheomelanin content increases only slightly, whereas 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-eumelanin and to a greater extent 5,6-dihydroxyindole (DHI)-eumelanin content are both markedly elevated. Analysis of the relative composition of epidermal melanin in these subjects revealed that DHI-eumelanin is the largest single component (approximately 60-70%), followed by DHICA-eumelanin (25-35%), with pheomelanin being a relatively minor component (2-8%). Moreover, there was a comparative enrichment of DHI-eumelanin at photoexposed sites, with a corresponding decline in the relative contributions from DHICA-eumelanin and pheomelanin. There was also a good correlation and close agreement between the concentration of spheroidal melanosomes determined by morphological image analysis and the concentration of pheomelanin determined by a combination of HPLC and spectrophotometric analysis (r = 0.89, P < 0.02). This study demonstrates the usefulness of melanosome morphology analysis as a sensitive new method for the quantification of melanin composition in human skin. The data also suggest that DHI-eumelanin formation is the dominant pathway for melanin synthesis in heavily pigmented (Fitzpatrick V and VI) skin types in vivo, and is the favoured pathway when melanin production is increased in chronically photoexposed skin.

Tophaceous gout of the spine mimicking epidural infection: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Tophaceous gout uncommonly affects the axial skeleton. The clinical presentations of gout of the spine range from back pain to quadriplegia. Gout that presents as back pain and fever may be difficult to distinguish from spinal infection. We present a case of a patient with tophaceous gout of the lumbar spine who was initially diagnosed with and treated for an epidural infection. The clinical and diagnostic features of tophaceous gout of the spine are reviewed.

CLINICAL PRESENTATION

A 70-year-old man presented with a 2-day history of fever and back pain. A physical examination revealed that he had flank tenderness and evidence of polyarthritis affecting the elbows, knees, and right first metatarsophalangeal joint. A magnetic resonance imaging scan of the patient's lumbar spine showed an extensive area of abnormal gadolinium enhancement of the paramedian posterior soft tissues from L3 to S1 with an area of focal enhancement extending into the right L4-L5 facet joint.

INTERVENTION

A laminectomy was performed at L4-L5, and a chalky white material in the facet joint was found eroding into the adjacent pars intra-articularis. Light and polarizing microscopy confirmed the presence of gouty tophus. No evidence of infection was found.

CONCLUSION

Gouty arthritis of the spine is rare. Thirty-seven previous cases have been reported. When the clinical presentation includes acute back pain and fever, differentiation of spinal gout from spinal infection may be difficult. The clinical suspicion of spinal gout may lead to the correct diagnosis by a less invasive approach than exploration and laminectomy.

Evaluation of the performance of full-scale packed saturators

An evaluation of the performance of full-scale packed saturators was made. Measurements of saturator effluent air concentrations, saturator efficiency and precipitated are reported for both cold water and warm water operating conditions. Packed saturators were analyzed over a full range of operating pressures and loading rates. Measured results compared to predicted results based on a comprehensive model for the performance of packed saturators prove the model to be a useful tool in designing efficient and cost effective saturation systems.

Editor's choice: the plight of a people dispossessed: caring for street children in the mountains of Bulgaria

This article was born out of a reflective diary kept by the author while working on a cross-community project in Northern Ireland. While it maps personal experiences, little did the author know its value in gaining insight and understanding of the eastern European situation that has now erupted with such devastating consequences.

The health effects of swimming in ocean water contaminated by storm drain runoff

Waters adjacent to the County of Los Angeles (CA) receive untreated runoff from a series of storm drains year round. Many other coastal areas face a similar situation. To our knowledge, there has not been a large-scale epidemiologic study of persons who swim in marine waters subject to such runoff. We report here results of a cohort study conducted to investigate this issue. Measures of exposure included distance from the storm drain, selected bacterial indicators (total and fecal coliforms, enterococci, and Escherichia coli), and a direct measure of enteric viruses. We found higher risks of a broad range of symptoms, including both upper respiratory and gastrointestinal, for subjects swimming (a) closer to storm drains, (b) in water with high levels of single bacterial indicators and a low ratio of total to fecal coliforms, and (c) in water where enteric viruses were detected. The strength and consistency of the associations we observed across various measures of exposure imply that there may be an increased risk of adverse health outcomes associated with swimming in ocean water that is contaminated with untreated urban runoff.

Assessment of Mild Head Injury with ERPs and Neuropsychological Tasks

Abstract Mild head injury can result in the development of persistent symptoms including impairments of memory and attention in a small but significant minority. The problem in assessing these difficulties in such cases is the likely interaction of psychogenic and organic causes. The aim of the present research is to more accurately characterize the nature of these cognitive deficits. Twelve asymptomatic volunteers, who had experienced a mild head injury in the last 3.5 years, were compared to a matched control group. ERPs were recorded during the performance of the paced auditory serial addition task (PASAT) and a 3-stimulus auditory “oddball” task. Verbal paired associate. Trails A and B, Digit Symbol, Rey Figure Recall, NART, and Digit Span were also administered. The mild head injured group showed evidence of a mild impairment of episodic memory, slowing of attention shifting, but no changes in reaction time or error rates in either the “oddball” task or the PASAT. Although there was no evidence of impairment of brain orienting responses in the 3-stimulus auditory oddball task, there was evidence of reduced frontal negativity associated with changes in task demand in the PASAT. This particular ERP feature appears similar to those associated with activation of selective attention mechanisms, thus suggesting that these asymptomatic individuals may be showing signs of a mild impairment of allocation of attention resources.

Myoblast city, the Drosophila homolog of DOCK180/CED-5, is required in a Rac signaling pathway utilized for multiple developmental processes

The Rac and Cdc42 GTPases share several regulators and effectors, yet perform distinct biological functions. The factors determining such specificity in vivo have not been identified. In a mutational screen in Drosophila to identify Rac-specific signaling components, we isolated 11 alleles of myoblast city (mbc). mbc mutant embryos exhibit defects in dorsal closure, myogenesis, and neural development. DOCK180, the mammalian homolog of Mbc, associates with Rac, but not Cdc42, in a nucleotide-independent manner. These results suggest that Mbc is a specific upstream regulator of Rac activity that mediates several morphogenetic processes in Drosophila embryogenesis.

The Rho GTPase and a putative RhoGEF mediate a signaling pathway for the cell shape changes in Drosophila gastrulation

The Rho GTPases mediate actin rearrangements that are likely to be required for the numerous cell shape changes in a developing embryo. In a genetic screen for Rho signaling pathway components in Drosophila, we identified a gene, DRhoGEF2, that encodes a predicted Rho-specific guanine nucleotide exchange factor. Embryos lacking DRhoGEF2 fail to gastrulate due to a defect in cell shape changes required for tissue invagination, and expression of a dominant-negative Rho GTPase in early embryos results in similar defects. Evidence is also presented that DRhoGEF2 mediates these specific cell shape changes in response to the extracellular ligand, Fog. Together, these results establish a Rho-mediated signaling pathway that is essential for the major morphogenetic events in Drosophila gastrulation.

Role of the beta 3-adrenergic receptor locus in obesity and noninsulin-dependent diabetes among members of Caucasian families with a diabetic sibling pair

Obesity and insulin resistance are important risk factors for the development of noninsulin-dependent diabetes (NIDDM) and are prevalent among predisposed first degree relatives of diabetic individuals. Recent molecular screening and analysis of a common missense mutation of the beta 3-adrenergic receptor gene suggested this locus as a strong candidate for increased obesity, earlier age of diabetes onset, and insulin resistance. To test the hypothesis that the beta 3-adrenergic receptor locus affects diabetes susceptibility, obesity as measured by body mass index, and components of the insulin resistance syndrome, we examined the role of this region in families ascertained for two or more NIDDM siblings. Linkage analysis was conducted using both parametric and nonparametric analyses, including multipoint sibling pair analysis. We found no evidence for linkage to NIDDM as a dichotomous trait and no evidence for linkage to body mass index, waist/hip ratio, insulin levels, or glucose levels as quantitative traits or to reported age of onset among NIDDM individuals. The Trp64 Arg missense mutation was present in 11% of the population. The mutation was not associated with NIDDM, and Arg64 carriers did not have earlier NIDDM onset, higher body mass index, or higher waist/hip ratio than Trp64 homozygotes. Among relatives, Arg64 carriers had significantly lower fasting glucose levels and lower waist/hip ratios than Trp64 homozygotes, but no characteristics of the insulin resistance syndrome. We conclude that the beta 3-adrenergic receptor locus does not play an important role in NIDDM susceptibility or in the insulin resistance syndrome among members of families with a strong predisposition to NIDDM.

Serial myoglobin levels for patients with possible myocardial infarction

OBJECTIVES

To determine the sensitivity and specificity of a new myoglobin assay for acute myocardial infarction (AMI), considering both the total amount of serum myoglobin and its percentage change over 2 hours.

METHODS

A prospective, observational test performance study for the recognition of AMI was done using serial myoglobin assays of 42 admitted chest pain patients at a large, urban teaching hospital ED. Myoglobin testing was performed at presentation (time 0) and at 1 and 2 hours after arrival. A myoglobin level > 100 micrograms/L (ng/mL) or a change > or = 50% from baseline (increase or decrease) any time during the 2-hour period was considered positive. Patients and their physicians were blinded to the myoglobin results. The managing clinician's final diagnosis of the presenting event was used as the diagnostic criterion standard.

RESULTS

The sensitivity of the myoglobin technique for detection of AMI in the first hours in the ED was 13/14 (93%; 95% CI: 66-100%). The 1 patient who had a false-negative test had evidence of AMI on the ECG and an initially abnormal creatine kinase-MB (CK-MB) assay. The specificity was 22/28 (79%; 59-92%). However, of the 6 patients who had "false-positive" myoglobin tests, all had serious illness: significant cardiac disease (n = 4), in-hospital death (n = 1), or deep venous thrombosis (n = 1).

CONCLUSION

Myoglobin level determinations are sensitive tests to detect AMI during the first 2 hours of a patient's stay in the ED and may complement current clinical tools.

A comparison of symptoms experienced following minor head injury and acute neck strain (whiplash injury)

The symptoms reported by patients who have experienced minor head or minor neck injury are compared. Symptoms were identified using a questionnaire-based out-patients interview. Rank order correlation analyses were carried out on data obtained at 2 and 6-12 weeks post-injury. Data on 24 head-injured and 29 neck-injured patients are presented. There was a significant rank order correlation at both assessments but neck injured patients reported more phobia (fear of travelling in car) and depression, and head-injured more dizziness. It is likely that neck-injury contributes to the symptomatology experienced after minor head injury, and vice-versa.

Home environment and adaptive social behavior among premature, low birth weight children: alternative models of environmental action

Used data from 465 premature, low birth weight children representing three major sociocultural groups (Caucasian, African American, Hispanic) to examine the relation between children's home environments and their adaptive social behavior. Results showed low to moderate associations between scores on the HOME Inventory at 1 and 3 years and scores on two measures of adaptive social behavior at 30 to 36 months, the Adaptive Social Behavior Inventory, and observations of mother-child interaction in a structured laboratory situation. Results indicated that responsive, nurturant care at both 1 and 3 years are related to child adaptive social behavior, as are cognitively stimulating experiences and materials. However, canonical correlational analysis indicated that only Acceptance and Variety of Experience, measured at age 3, and Variety of Experience measured at age 1 accounted for independent amounts of variance in adaptive social behavior as perceived by mothers. Also, only sociocultural group status and Learning Materials at 36 months contributed to the prediction of persistence and enthusiasm as observed in the laboratory setting.

Ketorolac versus meperidine-plus-promethazine treatment of migraine headache: evaluations by patients

This study was designed to compare and contrast the speed and efficacy of meperidine (75 mg)/promethazine (25 mg) intramuscularly to ketorolac (60 mg) intramuscularly, in a double-blind study in reducing the symptoms of migraine headache. Forty-two patients who presented to the emergency department between July 1992 and February 1993, with previous diagnoses of migraine headache, were considered for this study. Patients subjectively evaluated parameters of their migraine headaches (eg, pain and nausea) using a numeric scale and were later asked to reevaluate these same parameters at 30, 60, and 360 minutes after a single intramuscular injection of either ketorolac (60 mg) or meperidine (75 mg)/promethazine (25 mg). Sixty-eight percent of patients given meperidine/promethazine responded whereas 55% of patients given ketorolac responded. The responder group showed a statistically significant reduction in headache within 30 minutes with both drug regimens. There was no statistically significant difference between the number of responders in either group. The responders from both groups had relief that lasted 6 hours after injection. In the nonresponder groups, most of the patients withdrew within 1 hour after treatment. As determined by patient response to treatment of their migraine headaches, there was no statistically significant difference between the ketorolac and the meperidine/promethazine groups.

cAMP regulates morphogenesis in the fungal pathogen Ustilago maydis

The fungal pathogen Ustilago maydis exhibits a dimorphic switch from budding to filamentous growth in response to mating interactions and environmental conditions. We have found that disruption of the uac1 gene, encoding adenylate cyclase, results in a constitutively filamentous phenotype. Budding is restored to the uac1 mutant upon growth in the presence of cAMP or by extragenic suppression because of a mutation in the ubc1 gene. The ubc1 gene encodes a type II regulatory subunit of cAMP-dependent protein kinase (PKA); defects in this gene attenuate the filamentous growth that normally occurs in response to mating and exposure to air. Growth of wild-type cells in cAMP and mutation of the ubc1 gene also cause defects in the separation of mother and daughter cells (cytokinesis) and alter bud site selection. These results indicate a key role for cAMP and PKA in morphogenesis in U. maydis; this role may be common among dimorphic fungal pathogens.

Acetabular fractures: long-term follow-up of open reduction and internal fixation

Eight-seven acetabular fractures in eighty-seven patients underwent open reduction and internal fixation at Vanderbilt University Hospital from 1984 to 1989. Fifty-six were treated by orthopaedic traumatologists. Fifty-six patients returned for long-term follow-up (range 24-80 months, average 43). Harris hip ratings were used to clinically grade the results. Poor results were found in 43%. Eighty-three percent of the patients with poor results had satisfactory surgical reductions with < 3 mm of residual displacement. Factors other than surgical reduction contributed significantly to the poor results. These included hip dislocation associated with the fracture, class III or IV heterotopic ossification, development of avascular necrosis, and age > 40 years. These factors in addition to adequacy of surgical reduction allow us to better counsel patients as to long-term prognosis.

Characterization of ligand binding by the human p55 tumour-necrosis-factor receptor. Involvement of individual cysteine-rich repeats

Two soluble tumour-necrosis-factor-alpha(TNF)-binding proteins are derived from the extracellular domains of the p55 and p75 TNF receptors. They are considered to play a pivotal regulatory role in TNF-mediated inflammatory processes, including diseases such as rheumatoid arthritis, by competing with the cell surface receptors for TNF and lymphotoxin (LT, tumour-necrosis factor beta). The extracellular domains of the two receptors each contain four similar cysteine-rich repeats of about 40 amino acids, in common with several other cell surface proteins including the p75 nerve-growth-factor receptor and the CD40 and Fas antigens. The aim of this study was to characterize the involvement of the four cysteine-rich repeats of the human p55 TNF receptor in TNF and LT binding by both membrane-bound and soluble forms of the receptor. Individual repeats were systematically deleted by PCR mutagenesis and the variants transiently expressed in COS cells. Immunoprecipitated receptor variants exhibited the expected sizes on SDS/PAGE gels, and bound a panel of conformation-dependent anti-(TNF receptor) antibodies. Binding of TNF by the four soluble derivatives was compared with binding by the wild-type soluble receptor using a TNF-affinity column and a BIAcore Biosensor, by measurement of their ability to inhibit TNF cytotoxicity on WEHI cells, and 125I-TNF binding to U937 cells. delta 4, which lacks the fourth cysteine-rich repeat, bound TNF comparably with the full-length soluble receptor. TNF-binding affinity was unaltered by deletion of the fourth membrane-proximal cysteine-rich repeat, as determined by Scatchard analysis of the transmembrane derivatives. We conclude that the fourth cysteine-rich repeat is not required for TNF binding. In contrast, both the soluble and the transmembrane derivatives lacking any one of the first, second or third repeats failed to bind TNF. Although we cannot entirely exclude the possibility that this may be due to indirect conformational change, rather than the removal of essential epitopes, our results suggest that the first three repeats are each required for TNF binding by both the soluble and the cell-surface receptor.