The neural substrates of transdiagnostic cognitive-linguistic heterogeneity in primary progressive aphasia

BACKGROUND

Clinical variants of primary progressive aphasia (PPA) are diagnosed based on characteristic patterns of language deficits, supported by corresponding neural changes on brain imaging. However, there is (i) considerable phenotypic variability within and between each diagnostic category with partially overlapping profiles of language performance between variants and (ii) accompanying non-linguistic cognitive impairments that may be independent of aphasia magnitude and disease severity. The neurobiological basis of this cognitive-linguistic heterogeneity remains unclear. Understanding the relationship between these variables would improve PPA clinical/research characterisation and strengthen clinical trial and symptomatic treatment design. We address these knowledge gaps using a data-driven transdiagnostic approach to chart cognitive-linguistic differences and their associations with grey/white matter degeneration across multiple PPA variants.

METHODS

Forty-seven patients (13 semantic, 15 non-fluent, and 19 logopenic variant PPA) underwent assessment of general cognition, errors on language performance, and structural and diffusion magnetic resonance imaging to index whole-brain grey and white matter changes. Behavioural data were entered into varimax-rotated principal component analyses to derive orthogonal dimensions explaining the majority of cognitive variance. To uncover neural correlates of cognitive heterogeneity, derived components were used as covariates in neuroimaging analyses of grey matter (voxel-based morphometry) and white matter (network-based statistics of structural connectomes).

RESULTS

Four behavioural components emerged: general cognition, semantic memory, working memory, and motor speech/phonology. Performance patterns on the latter three principal components were in keeping with each variant's characteristic profile, but with a spectrum rather than categorical distribution across the cohort. General cognitive changes were most marked in logopenic variant PPA. Regardless of clinical diagnosis, general cognitive impairment was associated with inferior/posterior parietal grey/white matter involvement, semantic memory deficits with bilateral anterior temporal grey/white matter changes, working memory impairment with temporoparietal and frontostriatal grey/white matter involvement, and motor speech/phonology deficits with inferior/middle frontal grey matter alterations.

CONCLUSIONS

Cognitive-linguistic heterogeneity in PPA closely relates to individual-level variations on multiple behavioural dimensions and grey/white matter degeneration of regions within and beyond the language network. We further show that employment of transdiagnostic approaches may help to understand clinical symptom boundaries and reveal clinical and neural profiles that are shared across categorically defined variants of PPA.

Temporal lobe perceptual predictions for speech are instantiated in motor cortex and reconciled by inferior frontal cortex

Humans use predictions to improve speech perception, especially in noisy environments. Here we use 7-T functional MRI (fMRI) to decode brain representations of written phonological predictions and degraded speech signals in healthy humans and people with selective frontal neurodegeneration (non-fluent variant primary progressive aphasia [nfvPPA]). Multivariate analyses of item-specific patterns of neural activation indicate dissimilar representations of verified and violated predictions in left inferior frontal gyrus, suggestive of processing by distinct neural populations. In contrast, precentral gyrus represents a combination of phonological information and weighted prediction error. In the presence of intact temporal cortex, frontal neurodegeneration results in inflexible predictions. This manifests neurally as a failure to suppress incorrect predictions in anterior superior temporal gyrus and reduced stability of phonological representations in precentral gyrus. We propose a tripartite speech perception network in which inferior frontal gyrus supports prediction reconciliation in echoic memory, and precentral gyrus invokes a motor model to instantiate and refine perceptual predictions for speech.

Decision-making under uncertainty for species introductions into ecological networks

Ecological communities are increasingly subject to natural and human-induced additions of species, as species shift their ranges under climate change, are introduced for conservation and are unintentionally moved by humans. As such, decisions about how to manage ecosystems subject to species introductions and considering multiple management objectives need to be made. However, the impacts of gaining new species on ecological communities are difficult to predict due to uncertainty in introduced species characteristics, the novel interactions that will be produced by that species, and the recipient ecosystem structure. Drawing on ecological and conservation decision theory, we synthesise literature into a conceptual framework for species introduction decision-making based on ecological networks in high-uncertainty contexts. We demonstrate the application of this framework to a theoretical decision surrounding assisted migration considering both biodiversity and ecosystem service objectives. We show that this framework can be used to evaluate trade-offs between outcomes, predict worst-case scenarios, suggest when one should collect additional data, and allow for improving knowledge of the system over time.

Verbal fluency tests assess global cognitive status but have limited diagnostic differentiation: evidence from a large-scale examination of six neurodegenerative diseases

Verbal fluency is widely used as a clinical test, but its utility in differentiating between neurodegenerative dementias and progressive aphasias, and from healthy controls, remains unclear. We assessed whether various measures of fluency performance could differentiate between Alzheimer's disease, behavioural variant of frontotemporal dementia, non-fluent and semantic variants of primary progressive aphasia, progressive supranuclear palsy, corticobasal syndrome and healthy controls. Category and letter fluency tasks were administered to 33 controls and 139 patients at their baseline clinical visit. We assessed group differences for total number of words produced, psycholinguistic word properties and associations between production order and exemplar psycholinguistic properties. Receiver operating characteristic curves determined which measure could best discriminate patient groups and controls. The total word count distinguished controls from all patient groups, but neither this measure nor the word properties differentiated the patient groups. Receiver operating characteristic curves revealed that, when comparing controls to patients, the strongest discriminators were total word count followed by word frequency. Word frequency was the strongest discriminator for semantic variant of primary progressive aphasia versus other groups. Fluency word counts were associated with global severity as measured by Addenbrooke's Cognitive Examination Revised. Verbal fluency is an efficient test for assessing global brain-cognitive health but has limited utility in differentiating between cognitively and anatomically disparate patient groups. This outcome is consistent with the fact that verbal fluency requires many different aspects of higher cognition and language.

A 'Mini Linguistic State Examination' to classify primary progressive aphasia

There are few available methods for qualitatively evaluating patients with primary progressive aphasia. Commonly adopted approaches are time-consuming, of limited accuracy or designed to assess different patient populations. This paper introduces a new clinical test-the Mini Linguistic State Examination-which was designed uniquely to enable a clinician to assess and subclassify both classical and mixed presentations of primary progressive aphasia. The adoption of a novel assessment method (error classification) greatly amplifies the clinical information that can be derived from a set of standard linguistic tasks and allows a five-dimensional profile to be defined. Fifty-four patients and 30 matched controls were recruited. Five domains of language competence (motor speech, phonology, semantics, syntax and working memory) were assessed using a sequence of 11 distinct linguistic assays. A random forest classification was used to assess the diagnostic accuracy for predicting primary progressive aphasia subtypes and create a decision tree as a guide to clinical classification. The random forest prediction model was 96% accurate overall (92% for the logopenic variant, 93% for the semantic variant and 98% for the non-fluent variant). The derived decision tree produced a correct classification of 91% of participants whose data were not included in the training set. The Mini Linguistic State Examination is a new cognitive test incorporating a novel and powerful, yet straightforward, approach to scoring. Rigorous assessment of its diagnostic accuracy confirmed excellent matching of primary progressive aphasia syndromes to clinical gold standard diagnoses. Adoption of the Mini Linguistic State Examination by clinicians will have a decisive impact on the consistency and uniformity with which patients can be described clinically. It will also facilitate screening for cohort-based research, including future therapeutic trials, and is suitable for describing, quantifying and monitoring language deficits in other brain disorders.

Spanish Version of the Mini-Linguistic State Examination for the Diagnosis of Primary Progressive Aphasia

BACKGROUND

Primary progressive aphasia (PPA) is a neurodegenerative syndrome with three main clinical variants: non-fluent, semantic, and logopenic. Clinical diagnosis and accurate classification are challenging and often time-consuming. The Mini-Linguistic State Examination (MLSE) has been recently developed as a short language test to specifically assess language in neurodegenerative disorders.

OBJECTIVE

Our aim was to adapt and validate the Spanish version of MLSE for PPA diagnosis.

METHODS

Cross-sectional study involving 70 patients with PPA and 42 healthy controls evaluated with the MLSE. Patients were independently diagnosed and classified according to comprehensive cognitive evaluation and advanced neuroimaging.

RESULTS

Internal consistency was 0.758. The influence of age and education was very low. The area under the curve for discriminating PPA patients and healthy controls was 0.99. Effect sizes were moderate-large for the discrimination between PPA and healthy controls. Motor speech, phonology, and semantic subscores discriminated between the three clinical variants. A random forest classification model obtained an F1-score of 81%for the three PPA variants.

CONCLUSION

Our study provides a brief and useful language test for PPA diagnosis, with excellent properties for both clinical routine assessment and research purposes.

Language impairment in progressive supranuclear palsy and corticobasal syndrome

Although commonly known as movement disorders, progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) may present with changes in speech and language alongside or even before motor symptoms. The differential diagnosis of these two disorders can be challenging, especially in the early stages. Here we review their impact on speech and language. We discuss the neurobiological and clinical-phenomenological overlap of PSP and CBS with each other, and with other disorders including non-fluent agrammatic primary progressive aphasia and primary progressive apraxia of speech. Because language impairment is often an early and persistent problem in CBS and PSP, there is a need for improved methods for language screening in primary and secondary care, and more detailed language assessments in tertiary healthcare settings. Improved language assessment may aid differential diagnosis as well as inform clinical management decisions.

Language Disorder in Progressive Supranuclear Palsy and Corticobasal Syndrome: Neural Correlates and Detection by the MLSE Screening Tool

Background: Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) affect speech and language as well as motor functions. Clinical and neuropathological data indicate a close relationship between these two disorders and the non-fluent variant of primary progressive aphasia (nfvPPA). We use the recently developed Mini Linguistic State Examination tool (MLSE) to study speech and language disorders in patients with PSP, CBS, and nfvPPA, in combination with structural magnetic resonance imaging (MRI). Methods: Fifty-one patients (PSP N = 13, CBS N = 19, nfvPPA N = 19) and 30 age-matched controls completed the MLSE, the short form of the Boston Diagnostic Aphasia Examination (BDAE), and the Addenbrooke's Cognitive Examination III. Thirty-eight patients and all controls underwent structural MRI at 3 Tesla, with T1 and T2-weighted images processed by surface-based and subcortical segmentation within FreeSurfer 6.0.0 to extract cortical thickness and subcortical volumes. Morphometric differences were compared between groups and correlated with the severity of speech and language impairment. Results: CBS and PSP patients showed impaired MLSE performance, compared to controls, with a similar language profile to nfvPPA, albeit less severe. All patient groups showed reduced cortical thickness in bilateral frontal regions and striatal volume. PSP and nfvPPA patients also showed reduced superior temporal cortical thickness, with additional thalamic and amygdalo-hippocampal volume reductions in nfvPPA. Multivariate analysis of brain-wide cortical thickness and subcortical volumes with MLSE domain scores revealed associations between performance on multiple speech and language domains with atrophy of left-lateralised fronto-temporal cortex, amygdala, hippocampus, putamen, and caudate. Conclusions: The effect of PSP and CBS on speech and language overlaps with nfvPPA. These three disorders cause a common anatomical pattern of atrophy in the left frontotemporal language network and striatum. The MLSE is a short clinical screening tool that can identify the language disorder of PSP and CBS, facilitating clinical management and patient access to future clinical trials.

Spectroscopic and theoretical studies of UN and UN. J Chem Phys 2020;152:094302. [PMID: 33480743 DOI: 10.1063/1.5144299]

The low-energy electronic states of UN and UN⁺ have been examined using high-level electronic structure calculations and two-color photoionization techniques. The experimental measurements provided an accurate ionization energy for UN (IE = 50 802 ± 5 cm^-1). Spectra for UN⁺ yielded ro-vibrational constants and established that the ground state has the electronic angular momentum projection Ω = 4. Ab initio calculations were carried out using the spin-orbit state interacting approach with the complete active space second-order perturbation theory method. A series of correlation consistent basis sets were used in conjunction with small-core relativistic pseudopotentials on U to extrapolate to the complete basis set limits. The results for UN correctly obtained an Ω = 3.5 ground state and demonstrated a high density of configurationally related excited states with closely similar ro-vibrational constants. Similar results were obtained for UN⁺, with reduced complexity owing to the smaller number of outer-shell electrons. The calculated IE for UN was in excellent agreement with the measured value. Improved values for the dissociation energies of UN and UN⁺, as well as their heats of formation, were obtained using the Feller-Peterson-Dixon composite thermochemistry method, including corrections up through coupled cluster singles, doubles, triples and quadruples. An analysis of the ab initio results from the perspective of the ligand field theory shows that the patterns of electronic states for both UN and UN⁺ can be understood in terms of the underlying energy level structure of the atomic metal ion.

Eosinophil granule major basic protein 1 deposition in eosinophilic esophagitis correlates with symptoms independent of eosinophil counts

In patients with eosinophilic esophagitis (EoE), symptoms often do not correlate with peak eosinophil counts (PEC) determined on histopathological examination of biopsy specimens. This may be because eosinophils degranulate during active disease and lose their morphological identity as intact cells and, therefore, are not enumerated on microscopic examination. Eosinophil granule proteins that are released into tissues with degranulation, including major basic protein 1 (eMBP1), likely contribute to disease pathogenesis and, therefore, may correlate with symptoms better than PEC. We sought to determine whether symptoms in patients with EoE more closely relate to eosinophil granule protein deposition than to eosinophil enumeration, especially in patients with fewer than 15 eosinophils per high power field (HPF). Esophageal biopsy specimens from 34 patients diagnosed with EoE were obtained for histopathological examination and for evaluation of eMBP1 staining by indirect immunofluorescence. PEC by histopathology were compared to extracellular eMBP1 grades by immunostaining. PEC and eMBP1 grades also were analyzed for their relationship to symptoms and clinical course. Biopsy specimens from 19 of the 34 patients had fewer than 15 PEC on histopathological examination, and the other 15 patients had 15 or greater PEC. Positive eMBP1 immunostaining was found in all symptomatic patients. EoE symptoms were related to eMBP1 immunostaining grades (p = 0.0001), but not PEC (P = 0.14). Eosinophil granule protein deposition, specifically eMBP1, is increased in esophageal biopsy specimens from symptomatic patients with EoE and may be a marker of disease activity, including patients with EoE who have 'resolved' disease.

Structural correlates of cognitive impairment in normal pressure hydrocephalus

OBJECTIVES

The pathological bases for the cognitive and neuropsychiatric symptoms in normal pressure hydrocephalus (NPH) have not been elucidated. However, the symptoms may indicate dysfunction of subcortical regions. Previously, volume reductions of subcortical deep grey matter (SDGM) structures have been observed in NPH patients. The present study used automated segmentation methods to investigate whether SDGM structure volumes are associated with cognitive and neuropsychiatric measures.

METHODS

Fourteen NPH patients and eight healthy controls were included in the study. Patients completed neuropsychological tests of general cognition, verbal learning and memory, verbal fluency and measures of apathy and depression pre- and postshunt surgery. Additionally, patients underwent 3 Tesla T1-weighted magnetic resonance imaging at baseline and 6 months postoperatively. Controls were scanned once. SDGM structure volumes were estimated using automated segmentation (FSL FIRST). Since displacement of the caudate nuclei occurred for some patients due to ventriculomegaly, patient caudate volumes were also estimated using manual tracing. Group differences in SDGM structure volumes were investigated, as well as associations between volumes and cognitive and neuropsychiatric measures in patients.

RESULTS

Volumes of the caudate, thalamus, putamen, pallidum, hippocampus and nucleus accumbens (NAcc) were significantly reduced in the NPH patients compared to controls. In the NPH group, smaller caudate and NAcc volumes were associated with poorer performance on neuropsychological tests and increased severity of neuropsychiatric symptoms, while reduced volume of the pallidum was associated with better performance on the MMSE and reduced apathy.

CONCLUSIONS

Striatal volume loss appears to be associated with cognitive and neuropsychiatric changes in NPH.

Improvements in Attention Following Cognitive Training With the Novel "Decoder" Game on an iPad

Work and study increasingly rely on the use of technologies requiring individuals to switch attention rapidly between emails, texts and tasks. This has led to healthy people having problems of attention and concentration and difficulties getting into the “flow,” which impedes goal attainment and task completion. Possibly related to this, there is an increasing diagnosis of attention deficit hyperactivity disorder (ADHD) and prescriptions of drugs such as methylphenidate. In addition to ADHD, attention is impaired in other neuropsychiatric disorders, such as schizophrenia and in traumatic brain injury (TBI). Based on neuropsychological and neuroimaging evidence, we developed “Decoder,” a novel game for targeted cognitive training of visual sustained attention on an iPad. We aimed to investigate the effects of cognitive training in 75 healthy young adults randomly assigned to a Cognitive Training (8 h of playing Decoder over 4 weeks; n = 25), Active Control (8 h of playing Bingo over 4 weeks; n = 25) or Passive Control (continuation of activities of daily living; n = 25) group. Results indicated that cognitive training with Decoder was superior to both control groups in terms of increased target sensitivity (A’) on the Cambridge Neuropsychological Test Automated Battery Rapid Visual Information processing (CANTAB RVP) test, indicating significantly improved sustained visual attention. Individuals playing Decoder also showed significantly better performance on the Trail Making Test (TMT) compared with those playing Bingo. Significant differences in visual analogue scales were also found between the two gaming groups, such that Decoder received higher ratings of enjoyment, task-related motivation and alertness across all hours of game play. These data suggest that cognitive training with Decoder is an effective non-pharmacological method for enhancing attention in healthy young adults, which could be extended to clinical populations in which attentional problems persist.

Co-occurrence of eosinophilic esophagitis and potential/probable celiac disease in an adult cohort: a possible association with implications for clinical practice

We describe an adult cohort with eosinophilic esophagitis (EoE) and evidence of celiac disease (CD), propose a change in diagnostic practice to better characterize these conditions, and hypothesize new directions for research. Pediatric studies postulate association between gluten sensitivity and EoE. However, few publications describe the prevalence, detection, or therapeutic and pathophysiologic implications of such association in adults. Retrospective chart review was done on patients diagnosed with EoE from 2009 to 2010 at University of Utah Hospitals and Clinics. Data included sex, age, presentation, duodenal pathology, tissue transglutaminase immunoglobulin A antibody (TTG) positivity, human leukocyte antigen (HLA) type (when indicated), and gross and microscopic Esophagogastroduodenoscopy (EGD) findings. Duodenal biopsy, TTG results, and HLA type were correlated. Endoscopy was repeated after gluten-free diet. Forty-four of 75 patients were followed in EoE specialty clinic with duodenal biopsy and TTG testing per protocol. Six EoE patients had potential or probable CD. No sex or age differences were noted between those with findings of CD and EoE and those with EoE alone. Six patients with findings of CD and EoE followed gluten-free diet. Five underwent repeat endoscopy. Three had resolution of esophageal eosinophilia. Potential or probable CD was commonly found in adults with EoE. Diagnosis of CD may be challenging due to nonspecific symptoms and insufficient duodenal biopsy and serologic testing. Furthermore, gluten-free diet resolved EoE findings in some patients, suggesting possible shared pathophysiology in some cases of EoE and CD. TTG testing and adequate duodenal biopsy may further direct clinical care for EoE patients, and studies are needed to elucidate mechanisms linking EoE and CD.

The effect of shunt surgery on neuropsychological performance in normal pressure hydrocephalus: a systematic review and meta-analysis

We conducted a systematic review of the literature and used meta-analytic techniques to evaluate the impact of shunt surgery on neuropsychological performance in patients with normal pressure hydrocephalus (NPH). Twenty-three studies with 1059 patients were identified for review using PubMed, Web of Science, Google scholar and manual searching. Inclusion criteria were prospective, within-subject investigations of cognitive outcome using neuropsychological assessment before and after shunt surgery in patients with NPH. There were statistically significant effects of shunt surgery on cognition (Mini-Mental State Examination; MMSE), learning and memory (Rey Auditory Verbal Learning Test; RAVLT, total and delayed subtests), executive function (backwards digit span, phonemic verbal fluency, trail making test B) and psychomotor speed (trail making test A) all in the direction of improvement following shunt surgery, but with considerable heterogeneity across all measures. A more detailed examination of the data suggested robust evidence for improved MMSE, RAVLT total, RAVLT delayed, phonemic verbal fluency and trail making test A only. Meta-regressions revealed no statistically significant effect of age, sex or follow-up interval on improvement in the MMSE. Our results suggest that shunt surgery is most sensitive for improving global cognition, learning and memory and psychomotor speed in patients with NPH.

Endoscopic appearance and location dictate diagnostic yield of biopsies in eosinophilic oesophagitis

BACKGROUND

Acknowledging that eosinophilic esophagitis (EoE) is a disease with variable involvement throughout the oesophagus, studies have suggested a minimum of five biopsies to diagnose EoE. Although it is accepted that furrows and exudates appear to represent areas of inflammation, no research to date has looked specifically at EoE endoscopic findings to see if eosinophilic infiltrate correlates with specific endoscopic findings.

AIM

To evaluate the distribution of eosinophils in EoE and determine whether endoscopic appearances predict the degree of eosinophilia at various locations of the oesophagus.

METHODS

We performed a prospective cross sectional study of EoE (treated and untreated) patients to study the distribution of eosinophils according to endoscopic findings. The oesophagus of 10 EoE patients were biopsied up to 32 times in a circumferential manner. The mucosal changes were documented at the site of each biopsy. Histological determination of eosinophil counts and related histopathology of the oesophagus were then correlated with endoscopic findings. Similar biopsy assessments were made in treated (resolved) EoE patients (n = 6) to determine the permanence of specific endoscopic appearances.

RESULTS

A total of 16 patients were biopsied (10 EoE, 6 treated EoE). A total of 432 biopsies were obtained in all with 294 biopsies from 10 EoE subjects. Eosinophil density was increased distally in the majority of EoE patients. Biopsies performed in areas of exudates and furrows demonstrated higher eosinophil counts. Lines and normal-appearing oesophagi in EoE subjects were not commonly associated with elevated eosinophil counts (>15 eos/HPF). Rings alone without associated furrows or plaques did not demonstrate elevated eosinophil counts and were seen in resolved EoE (Rx-EoE) as well as in active EoE patients.

CONCLUSIONS

Eosinophilic esophagitis remains a variable disease with some patients manifesting extensive disease throughout the oesophagus. Characteristics of furrows and exudates found during endoscopy are associated with higher peak eosinophil counts, requiring fewer biopsies to make a diagnosis. Lines and otherwise normal appearances of the oesophagus suggest a milder mucosal eosinophilia, requiring substantial biopsies to adequately identify fields with diagnostic eosinophil counts.

Apathy, ventriculomegaly and neurocognitive improvement following shunt surgery in normal pressure hydrocephalus

INTRODUCTION

Apathy - impaired motivation and goal-directed behaviour - is a common yet often overlooked symptom in normal pressure hydrocephalus (NPH). Caudate atrophy often yields apathetic symptoms; however, this structural and functional relationship has not yet been explored in NPH. Additionally, little is known about the relationship between apathy and post-shunt cognitive recovery.

METHODS

This audit investigated whether apathetic symptoms improve following shunt surgery in NPH, and whether this relates to cognitive response. In addition, we assessed the relationship between ventriculomegaly and apathy using the bicaudate ratio. Twenty-two patients with NPH completed the Mini-Mental State Examination (MMSE), the Apathy Evaluation Scale (AES) and the Geriatric Depression Scale (GDS) before and 3-9 months after shunt surgery. Pre-operative ventriculomegaly was correlated with pre-operative AES and GDS scores. Difference scores (post-shunt minus baseline values) for AES and GDS were correlated with cognitive outcome.

RESULTS

Greater pre-operative ventriculomegaly was associated with increased level of apathy and depression. A reduction in apathetic symptoms following shunt surgery was associated with improved performance on the MMSE.

CONCLUSIONS

Apathy may be indicative of a greater degree of subcortical atrophy in NPH and may relate to functional outcome.

Molecular Structure, Spectroscopy and Matrix Photochemistry of Fluorocarbonyl Iodide, FC(O)I

The molecular structure of FC(O)I has been determined by gas electron diffraction. High-level ab initio methods, including coupled-cluster and the new correlation-consistent basis sets for fourth row elements, have been used to calculate the structure of FC(O)I. A comprehensive vibrational spectroscopic study (both IR and Raman) complemented by high-level calculations has also been performed. Furthermore, UV, mass, and NMR spectra have been recorded for FC(O)I. The matrix photochemistry of FC(O)I has been studied with a low-pressure mercury lamp and with a high-pressure xenon lamp in combination with interference and cut-off filters. UV photolysis revealed the formation of the OC. IF and OC.FI complexes and further photolysis of these complexes at lambda>320 nm resulted in a re-formation of FC(O)I. The structural conformation of the complexes has been characterized by comparing shifts in their CO and IF vibrational modes with respect to those of the free species. The structures, vibrational properties, and stability of the complexes were analyzed with the aid of coupled-cluster ab initio calculations.

Identification of human serum interferants in the recombinant P-selectin glycoprotein ligand-1 clinical ELISA using MALDI MS and RP-HPLC

A colorimetric enzyme-linked immunosorbent assay (ELISA) was developed to detect circulating levels of rPSGL to permit pharmacokinetic analysis of clinical samples. The ELISA is an asymmetric sandwich utilizing a monoclonal antibody pair. Initial validation studies indicated that 57% of normal individuals scored above the limit of detection of the assay. Specificity experiments indicated that the signal was not due to circulating endogenous P-selectin glycoprotein ligand-1 (PSGL-1). Using matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) and sampling within the individual microplate wells, the interferant was detected in the vicinity of 6.6 kDa in lipemic and normal human sera, but not delipidized sera. These results were consistent with the ELISA data where 97.5% of known lipemic, 57% of normal, and 0% of delipidized sera scored above detectable limits in the ELISA. Preparative isolations of the 6.6 kDa species were performed using reversed-phase high performance liquid chromatography (RP-HPLC) with UV and MS detection. Edman N-terminal sequencing identified the 6.6 kDa unknown as Apolipoprotein C-I. Additional apolipoproteins were found by MALDI and RP-HPLC. Digestion of sera with liposome lipase and extraction of sera with anti-apolipoprotein C-I, C-II, and C-III antibody beads significantly reduced the ELISA interference. These experiments combined with the MALDI detection of phosphatidylcholine-type lipids from NHS eluate suggested that lipoprotein particles or remnants were causing the interference. A method combining Triton-X 100 with sonication was developed to overcome this interference without altering rPSGL recovery in the ELISA.

Electric-field-induced second-harmonic generation in GaN devices

Electric-field-induced second-harmonic generation is used to detect electric fields in a GaN UV Schottky photodiode and in a GaN light-emitting diode. The second-harmonic signal is measured as a function of bias voltage and incident laser power. This technique is sensitive to small applied voltages and can be used to track electronic waveforms. The photocurrent generated by this technique is found to be less than 100 pA when the fundamental and second-harmonic frequencies are both below the device bandgap.

New directions in substance abuse services: programmatic innovations in the Veterans Administration

The purpose of this paper to describe the Department of Veterans Affairs' (VA) recent expansion and enhancement of its substance abuse treatment services. Several treatment innovations are considered from both clinical and administrative perspectives. These services include extended care programs for multiply impaired patients, programs for substance abuse patients with comorbid psychiatry conditions and services designed to improve continuity of care and community re-entry. Emergent themes include a broadening of services to meet the needs of a changing substance abuse population and an emphasis on providing more cost-efficient treatment.

High-sensitivity detection of CH radicals in flames by use of a diode-laser-based near-ultraviolet light source

CH radical distributions in ethylene-air and methane-air diffusion flames are mapped by wavelength-modulation absorption spectroscopy (WMS). Tunable, wavelength-modulated 426-nm light is generated by frequency doubling of a modulated 852-nm distributed Bragg reflector diode laser. Absorbances of 5 x 10(-5) are measured with second-harmonic (2f) WMS with a signal-to-noise ratio of 3:1 in a 3-Hz measurement bandwidth. The feasibility of simultaneous line-of-sight absorption and spatially resolved laser-induced-fluorescence detection with a single excitation beam is also demonstrated. This near-UV source is suitable for microgravity drop-tower experiments and other applications in which compact, rugged, energy-efficient instrumentation is required.

Strategies to improve diabetes care delivery

Although the primary care office is an important location for integrating new advances in the treatment of diabetes, the current delivery of preventive primary care for patients with diabetes falls short of clinical recommendations. Barriers within the existing health care system, practice structure, and physician and patient support services are among the most commonly cited obstacles to initiating better preventive care. As public health groups demand greater accountability from the medical system, regulatory efforts focus more scrutiny on systems, clinic practices, and even individual physician practices. Although improving care delivery effectively and efficiently is difficult, strategies to exist that can increase the likelihood of improving patient outcomes. Successful diabetes initiatives are often characterized by the consensual adoption of an evidence-based treatment plan. Effective physician-oriented interventions include the use of reminder systems, local opinion leaders, and academic detailing. In addition, several national diabetes initiatives are likely to influence primary care practice. New measures of accountability will be widely used to determine the quality of primary diabetes care delivery.

Measuring substance abuse program treatment orientations: the Drug and Alcohol Program Treatment Inventory

Assessment of therapeutic orientation is a significant problem in substance abuse program evaluation. This study reports the initial results of a new approach to measuring treatment orientation through a self-report survey that focuses on distinctive features of substance abuse treatment orientations. The Drug and Alcohol Program Treatment Inventory (DAPTI) assesses treatment goals and activities specific to eight orientations: AA/12 Step, Therapeutic Community, Cognitive-Behavioral, Insight/Psychodynamic, Rehabilitation, Dual Diagnosis, Medical and Marital/Family Systems. We present findings from a nationwide assessment of 327 Veterans Administration (VA) Substance Abuse treatment programs that demonstrate promising subscale internal consistency, discriminant validity, and concurrent validity. In addition, the DAPTI distinguishes between programs with independently verified orientations and between inpatient, extended care, outpatient, and methadone maintenance programs. The DAPTI may be helpful in systematically assessing differences in treatment orientations between different types of programs, such as inpatient, community residential, and outpatient care.

Comparison of home glucose monitoring with the oral glucose tolerance test to detect gestational glucose intolerance

BACKGROUND

Recent evidence suggests that infant morbidity is increased among women who have abnormal prenatal glucose screening tests but who do not have gestational diabetes mellitus (GDM). These women fall into a diagnostic gray zone and historically have not been treated.

METHODS

Forty-eight pregnant women with abnormal oral glucose challenge test results performed self-monitored blood glucose (SMBG) testing seven times per day for 1 week before undergoing a diagnostic 100-g oral glucose tolerance test (OGTT). At delivery, perinatal complications and birthweights were recorded. Results of SMBG tests for women with normal OGTTs were correlated with infant birthweights.

RESULTS

Thirteen infants (37%) were found to be large for gestational age (LGA). Significant correlation was found between increasing birthweight and increasing average fasting SMBG values (P < .001), increasing percentage of SMBG values above 120 mg/dL (6.7 mmol/L) (P < .01), and increasing average SMBG values (P < .016).

CONCLUSIONS

Maternal home glucose values at 28 weeks correlate with the risk of LGA infant births among women in the diagnostic gray zone. Women with average fasting SMBG values > 95 mg/dL (5.3 mmol/L) are at increased risk for giving birth to LGA infants and may be more likely to exhibit complications usually associated with GDM.

Determinants of readmission following inpatient substance abuse treatment: a national study of VA programs

This study examines program determinants of one aspect of VA inpatient substance abuse treatment program performance. Performance was measured by the ratio of a program's readmission rate to the expected rate for programs with similar patients. Six-month readmission rates in 101 VA treatment programs were analyzed. Preliminary analyses indicated that patient differences across programs accounted for 36% of the variance in readmission rates. Program differences accounted for 47% of the variance in case-mix-adjusted readmission rate. Among program factors selected through a literature review, better than expected readmission performance was associated with having fewer early discharges, a longer intended treatment duration, more patient participation in aftercare, more family or friend assessment interviews, and treating more patients on a compulsory basis. Performance was not related to stress management training, patient attendance at more self-help meetings during treatment, staff characteristics, or average staff costs per patient day. The findings indicate that treatment retention, duration, and increased aftercare may be targeted to reduce high readmission rates. Last, there were only small differences in the model over 30, 60, 90, and 365 day follow-up intervals, suggesting substantial stability of the findings.

Diabetes care by primary care physicians in Minnesota and Wisconsin

BACKGROUND

The purpose of this study was to identify the characteristics of diabetes care delivered by primary care physicians.

METHODS

Twenty-seven primary care physicians recruited through the Minnesota Academy of Family Physicians Research Network and the Wisconsin Research Network recorded a sample of 240 visits for care of patients with diabetes mellitus. Information was collected concerning physician and patient demographics, practice characteristics, and patterns of delivery of diabetes care including referral and clinical outcomes.

RESULTS

Seventeen percent of the patients in this study had type I diabetes mellitus; 81% had type II. Fourteen percent of the patients with type I diabetes and 20% of patients with type II were within their target glucose range. Average hemoglobin-A1c was 10.0% +/- 3.4% and 8.9% +/- 2.3% for patients with type I and type II diabetes, respectively (normal, 4.0% to 6.1%). Two distinct patterns of referral existed for patients with newly diagnosed type I diabetes: 44% of physicians rarely referred these patients, whereas 20% almost always referred. Although distance to specialists increased as community size decreased, frequency of referral was not related to practice location. Ninety-five percent of physicians in this study were directly involved in the diabetes education of their patients, and 56% had no certified diabetes educator available.

CONCLUSIONS

Over the course of this study, patients frequently persisted with treatment regimens that failed to stabilize blood glucose values. With recent evidence that improved glucose control may delay or prevent diabetes complications, it is increasingly important for the primary care physician to optimize available resources to improve glucose control in patients with diabetes in an effort to improve long-term clinical outcomes.

Picosecond infrared study of the photodynamics of carbonmonoxy-cytochrome c oxidase

Time-resolved infrared (TRIR) techniques have been employed to study the reactions of carbon monoxide with the cytochrome alpha 3-Cu(B) site of cytochrome c oxidase (CcO). The ligation dynamics immediately following photodissociation have been investigated using picosecond TRIR spectroscopy and linear dichroism. The rate of photoinitiated transfer of CO from cytochrome alpha 3 to CuB was measured directly by monitoring the development of the transient CuBCO absorption. In less than 1 ps, a stationary CuBCO spectrum develops, which together with the CO infrared linear dichroism is constant until the CO dissociates from CuB on a microsecond time scale. These observations indicate that the CO is transferred between metals and reaches its equilibrium conformation in less than 1 ps. This unprecedented ligand transfer rate has profound implications with regard to the structure and dynamics of the cytochrome alpha 3-CuB site, the functional architecture of the protein, and coordination dynamics in general.

The psychosocial effects of support group intervention on AICD recipients and their significant others

The automatic implantable cardioverter defibrillator (AICD) is one treatment method employed for patients with actual or potential malignant ventricular tachyarrhythmias. Support group intervention has been shown to be of value in promoting adaptation and coping skills. This exploratory pilot study compared the psychosocial effects of support group intervention on 11 AICD recipients who regularly attended support group, ten spouses, or significant others who also attended and five AICD recipients who were unable to attend. The Spielberger State Anxiety Inventory, The Anxiety Visual Analogue Study (VAS), the Medical Outcome Study (MOS) Short Form General Health Survey, and anecdotal reports were used. Results showed that quantitative data were not significantly changed by support group interventions. Qualitative data demonstrated improved ability to cope and increased satisfaction with life in group participants, however, it was difficult to ascertain whether this was a result of passage of time.

Symptom monitoring in schizophrenia: potential for enhancing self-care

In this study a symptom self-regulation model was used as a framework to examine the characteristics and stability of indicators of illness identified by individuals with schizophrenia. Subjects were interviewed to determine if they could identify indicators of illness and describe characteristics of their primary indicator. Primary indicators of illness from 51 subjects were categorized as anxiety-based, depressive, or psychotic. Subjects who identified psychotic indicators were more confident that their indicator occurred when they were getting ill than subjects with anxiety-based or depressive indicators, and subjects who identified psychotic and depressive indicators reported that their indicators were more troublesome than those identifying anxiety-based indicators. Anxiety-based indicators were reported by subjects to occur more frequently than indicators from the other two categories. Findings from a follow-up interview of 28 subjects 1 year later showed that approximately half reported either the same primary indicator of illness or identified an indicator in the same category (anxiety-based, depressive, or psychotic) as they had 1 year previously. The implications of the findings for enhancing self-care through monitoring symptoms are discussed.

Interleukin 2 receptor expression in patients with head and neck squamous carcinoma. Effects of thymosin alpha 1 in vitro

Altered cellular immunity in patients with advanced head and neck cancer includes impairments in lymphokine production, blastogenesis, in vitro cytotoxicity, and T-cell levels. Recent evidence for the potential importance of in lymphokine interleukin 2 (IL-2) in patients with cancer prompted a study of the kinetics of IL-2 receptor expression on lymphocytes from patients with untreated advanced head and neck cancer and normal subjects and an evaluation of the in vitro effects of the T-cell immune-reconstituting peptide, thymosin alpha 1. Concanavalin A-stimulated IL-2 receptor expression was maximal after 72 hours and was higher in normal subjects than in patients. This was due to lower levels of helper/inducer (CD4) cells expressing IL-2 receptors in the patients compared with the normal subjects. Thymosin alpha 1 further decreased levels of IL-2 receptor-positive (both CD4 and CD8) cells at 48 and at 72 hours. At 96 hours, levels of IL-2 receptor-positive cells and proportions of cells in G2 and M phases of the cell cycle were similar among both groups of subjects. Simultaneous cell kinetic studies indicated that thymosin alpha 1 down regulation of IL-2 receptors was not due to an effect on proliferation and that differences in IL-2 receptor expression at 72 hours among normal subjects and the patients with cancer were more likely related to differences in cell proliferation kinetics.

Alterations in T-lymphocyte subpopulations in patients with head and neck cancer. Correlations with prognosis

Impaired cell-mediated immunity has been consistently demonstrated in patients with advanced head and neck squamous cancer (HNSC); however, the results of prior studies of correlations of cellular immune parameters with treatment outcome have been inconsistent, and routine assessment of immune parameters has been of limited clinical use. To determine the prognostic importance of alterations in the proportions of various T-lymphocyte subpopulations in the peripheral blood of patients with HNSC, levels of T3, T4, T6, T8, T9, T10, T11, and Leu 7 cells were quantitated by flow cytometry in 80 previously untreated patients and prospectively correlated with tumor characteristics and clinical course (median length of follow-up, 27 months). The mean helper/suppressor cell ratio (T4/T8) increased progressively with increasing tumor stage and was significantly elevated among patients with cancer as a group and in patients with advanced (stage III or IV) disease compared with 40 normal subjects. Decreased disease-free survival was significantly associated with elevated T4/T8 ratios and low percent T8 and T11 cell levels. The prognostic significance of percent T8 (cytotoxic/suppressor) cell levels persisted even after adjusting for known prognostic factors of tumor stage, T class, N class, and tumor site. These correlations provide new insight into immune alterations in HNSC that may prove useful in identifying patients with early clinical disease who have a poor prognosis.

Use of symptoms by schizophrenics to monitor and regulate their illness

Interviews with 62 outpatients with chronic schizophrenia and schizoaffective disorder indicated that many patients monitor symptoms that they associate with changes in their illness and alter their behavior based on their symptoms. Ninety-eight percent of the subjects identified symptoms, two-thirds of which were nonpsychotic, that indicated to them they were getting worse. Eighty-two percent of those who identified symptoms of decompensation responded by altering their behavior, either by self-treatment (such as self-medicating, engaging in a diversionary activity, or attempting to ignore the symptoms), by seeking mental health assistance, or both. The authors compare their findings with those of other studies and discuss the study's implications for research on and care of schizophrenic patients.

Lymphocyte subpopulations infiltrating squamous carcinomas of the head and neck: correlations with extent of tumor and prognosis

Because little is known about the mechanisms involved in local tumor-host immune reactions in squamous carcinoma of the head and neck, a study was undertaken to better characterize the types of immune cells present at the local tumor site and determine their relationship to tumor extent, systemic cellular immune parameters, and clinical outcome. In 40 untreated patients, lymphocyte subsets (LS) at the tumor-host interface were quantitated immunohistologically from serial sections of frozen tumor specimens and correlated with concurrently measured peripheral LS levels and in vitro lymphocyte reactivity to phytohemagglutinin (PHA). The majority of infiltrating lymphocytes were T cells with rare B or Leu 7 cells. Proportions of T4 and T8 were similar in peritumor stroma; however, T8 cells predominated tumor parenchyma. Stromal and parenchymal infiltration by LS were not related to peripheral blood LS levels, lymphocyte reactivity, or tumor site. However, parenchymal T11 and T4 cell infiltration was less in advanced primary tumors (T3, T4) than in early tumors (T1, T2) (P = 0.01, P = 0.067, respectively), as was peripheral lymphocyte reactivity to PHA (P = 0.013). Short-term disease-free interval and actuarial survival differed significantly--according to parenchymal T11 and T4 cell infiltration--and were not related to T8, Leu 7, and B-cell infiltration. The findings extend prior studies of lymphocytic infiltration in head and neck cancer and demonstrate the potential importance of differences in tumor stromal and parenchymal infiltration. Together with recent evidence that T4 cells are critical for lymphokine production and for the proliferation of cytotoxic effector cells, the current results suggest that T4 cells play a critical role in the local immune response in squamous carcinoma of the head and neck.

Beta endorphin enhances in vitro lymphokine production in patients with squamous carcinoma of the head and neck

Recent studies of the effects of endorphins and other neuropeptides on immune mechanisms suggest that immune reactive cells have specific opioid-like and nonopioid endorphin receptors, and indicate that neuropeptides may participate in regulating in vivo immune functions. Earlier demonstrations of impaired cellular immunity and impaired lymphokine production in patients with cancer of the head and neck prompted an investigation of the in vitro effects of beta-endorphin on the production of leukocyte migration inhibitory factor (LIF) in 29 patients with head and neck cancer and in 45 normal subjects. LIF production in response to phytohemagglutinin was significantly less in the cancer patients compared to normal subjects (p less than .001). beta-endorphin significantly enhanced LIF production in the cancer patients (p = .01) to levels that did not differ significantly from normal levels. A correlation of levels of lymphocyte subpopulations in the cancer patients suggested that enhancement of lymphokine production by beta-endorphin was related to levels of T8 (suppressor/cytotoxic) cells. The results confirm earlier demonstrations of impaired lymphokine production in patients with head and neck cancer and indicate that beta-endorphin can modulate in vitro lymphokine responses in such patients. These findings suggest that neuroendocrine peptides may play an important role in regulating immune function. Further study of the role of neuropeptides in the immune response should provide additional insight into the characterization of cellular immune dysfunction associated with head and neck cancer and should lead to the development of innovative immunotherapeutic treatment strategies.

Definite vs adjuvant radiotherapy. Comparative effects on lymphocyte subpopulations in patients with head and neck squamous carcinoma

The recent association of alterations in T-lymphocyte subpopulations and impaired cellular immunity prompted an investigation of the effects of radiotherapy (RT) on serial levels of lymphocyte subsets in 30 patients with head and neck squamous carcinoma. Percentage and absolute levels of T3, T4, T6, T8, T10, T11, and Leu 7 cells were measured before, during, and after RT at monthly intervals for six months and compared with levels in 40 normal subjects. Sixteen patients received curative and 14 postoperative adjuvant RT. Before treatment, mean subset levels were similar among the patient and normal groups except for elevated Leu 7 (natural killer) cells in patients with stage I and II disease. There were profound decreases in absolute levels of each subpopulation during and after RT. The percentage of T4 (helper/inducer) cells decreased, whereas that of T8 (cytotoxic/suppressor) and Leu 7 cells tended to increase. Compared with normal values, the mean T4/T8 ratio decreased significantly by six months after RT, when absolute levels of the subsets had rebounded to pretreatment levels in the definitive RT group but remained profoundly decreased in the adjuvant group. The differing recovery patterns suggest that factors other than RT may contribute to persistent immunosuppression following RT.

In vitro immune modulation by thymosin alpha 1 in patients with head and neck squamous cell carcinoma

To determine if patients with head and neck squamous cell carcinoma represent an appropriate population for immune reconstitution with thymosin alpha 1, leukocyte migration inhibition (LMI) in response to phytohemagglutinin was measured in 24 previously untreated patients with head and neck cancer, and the in vitro effects of thymosin alpha 1 on migration inhibition were assessed. Compared to normal subjects, LMI was impaired in the head and neck cancer patients. Thymosin alpha 1, in vitro, was associated with improvement in LMI in the cancer patients. Improvements in migration response with thymosin alpha 1 appeared to be independent of levels of various T-lymphocyte subpopulations. However, patients with a normal LMI response had lower suppressor/cytotoxic cell levels than normal subjects or patients with impaired LMI. The findings confirm prior reports of the effects of thymic hormones on lymphokine production in vitro and provide rationale for further clinical studies of thymosin alpha 1 in patients with head and neck squamous cell carcinoma.