Early Infant Prefrontal Cortical Microstructure Predicts Present and Future Emotionality

BACKGROUND

High levels of infant negative emotionality (NE) and low positive emotionality (PE) predict future emotional and behavioral problems. The prefrontal cortex (PFC) supports emotional regulation, with each PFC subregion specializing in specific emotional processes. Neurite Orientation Dispersion and Density Imaging (NODDI) estimates microstructural integrity and myelination via the neurite density index (NDI) and dispersion via the orientation dispersion index (ODI), with potential to more accurately evaluate microstructural alterations in the developing brain. Yet, no study has used these indices to examine associations between PFC microstructure and concurrent or developing infant emotionality.

METHODS

We modeled PFC subregional NDI and ODI at 3 months with caregiver-reported infant NE and PE at 3 months (n=61) and at 9 months (n=50), using multivariable and subsequent bivariate regression models.

RESULTS

The most robust statistically-significant findings were positive associations among 3-month rACC ODI and cACC NDI and concurrent NE, and 3-month lOFC ODI and prospective NE; and a negative association between 3-month dlPFC ODI and concurrent PE. Multivariate models also revealed that other PFC subregional microstructure measures, and infant and caregiver sociodemographic and clinical factors, predicted infant 3- and 9-month NE and PE.

CONCLUSIONS

Greater NDI and ODI, reflecting greater microstructural complexity, in PFC regions supporting salience perception (rACC), decision-making (lOFC), action selection (cACC), and attentional processes (dlPFC) might result in greater integration of these subregions with other neural networks, greater attention to salient negative external cues, thus higher NE and/or lower PE. These findings provide potential infant cortical markers of future psychopathology risk.

Early infant prefrontal gray matter volume is associated with concurrent and future infant emotionality

High levels of infant negative emotionality (NE) are associated with emotional and behavioral problems later in childhood. Identifying neural markers of high NE as well as low positive emotionality (PE) in infancy can provide neural markers to aid early identification of vulnerability, and inform interventions to help delay or even prevent psychiatric disorders before the manifestation of symptoms. Prefrontal cortical (PFC) subregions support the regulation of NE and PE, with each PFC subregion differentially specializing in distinct emotional regulation processes. Gray matter (GM) volume measures show good test-retest reliability, and thus have potential use as neural markers of NE and PE. Yet, while studies showed PFC GM structural abnormalities in adolescents and young adults with affective disorders, few studies examined how PFC subregional GM measures are associated with NE and PE in infancy. We aimed to identify relationships among GM in prefrontal cortical subregions at 3 months and caregiver report of infant NE and PE, covarying for infant age and gender and caregiver sociodemographic and clinical variables, in two independent samples at 3 months (Primary: n = 75; Replication sample: n = 40) and at 9 months (Primary: n = 44; Replication sample: n = 40). In the primary sample, greater 3-month medial superior frontal cortical volume was associated with higher infant 3-month NE (p < 0.05); greater 3-month ventrolateral prefrontal cortical volume predicted lower infant 9-month PE (p < 0.05), even after controlling for 3-month NE and PE. GM volume in other PFC subregions also predicted infant 3- and 9-month NE and PE, together with infant demographic factors, caregiver age, and/or caregiver affective instability and anxiety. These findings were replicated in the independent sample. To our knowledge, this is the first study to determine in primary and replication samples associations among infant PFC GM volumes and concurrent and prospective NE and PE, and identify promising, early markers of future psychopathology risk.

Neural Network Functional Interactions Mediate or Suppress WM-Emotional Behavior Relationships in Infants

BACKGROUND

Elucidating the neural basis of infant positive emotionality (PE) and negative emotionality (NE) can identify biomarkers of pathophysiological risk. Our goal was to determine how functional interactions among large-scale networks supporting emotional regulation influence WM microstructural-emotional behavior relationships in 3-month-old infants. We hypothesized that microstructural-emotional behavior relationships would be differentially mediated or suppressed by underlying resting-state functional connectivity (rsFC), particularly between Default Mode Network (DMN) and Central Executive Network (CEN) structures.

METHODS

The analytic sample comprised primary caregiver-infant dyads [52 infants (42% female, mean age at scan=15.10 weeks)], with infant neuroimaging and emotional behavior assessments at 3 months. Infant WM and rsFC were assessed by diffusion-weighted imaging/tractography and resting-state magnetic resonance imaging (MRI) during natural, non-sedated sleep. The Infant Behavior Questionnaire-R provided measures of infant PE and NE.

RESULTS

Following significant WM-emotional behavior relationships, multimodal analyses were performed using whole-brain voxelwise mediation. Results revealed that greater cingulum bundle volume was significantly associated with lower infant PE (ß = -0.263, p = 0.031); however, a pattern of lower rsFC between CEN and DMN structures suppressed this otherwise negative relationship. Greater uncinate fasciculus volume was significantly associated with lower infant NE (ß = -0.296, p = 0.022); however, lower orbitofrontal cortex (OFC)-amygdala rsFC, suppressed this otherwise negative relationship, while greater OFC-CEN rsFC mediated this relationship.

CONCLUSIONS

Functional interactions among neural networks have an important influence on WM microstructural-emotional behavior relationships in infancy. These relationships can elucidate neural mechanisms contributing to future behavioral and emotional problems in childhood.

Impaired Neurovascular Function Underlies Poor Neurocognitive Outcomes and Is Associated with Nitric Oxide Bioavailability in Congenital Heart Disease

We use a non-invasive MRI proxy of neurovascular function (pnvf) to assess the ability of the vasculature to supply baseline metabolic demand, to compare pediatric and young adult congenital heart disease (CHD) patients to normal referents and relate the proxy to neurocognitive outcomes and nitric oxide bioavailability. In a prospective single-center study, resting-state blood-oxygen-level-dependent (BOLD) and arterial spin labeling (ASL) MRI scans were successfully obtained from 24 CHD patients (age = 15.4 ± 4.06 years) and 63 normal referents (age = 14.1 ± 3.49) years. Pnvf was computed on a voxelwise basis as the negative of the ratio of functional connectivity strength (FCS) estimated from the resting-state BOLD acquisition to regional cerebral blood flow (rCBF) as estimated from the ASL acquisition. Pnvf was used to predict end-tidal CO2 (P_ETCO2) levels and compared to those estimated from the BOLD data. Nitric oxide availability was obtained via nasal measurements (nNO). Pnvf was compared on a voxelwise basis between CHD patients and normal referents and correlated with nitric oxide availability and neurocognitive outcomes as assessed via the NIH Toolbox. Pnvf was shown as highly predictive of P_ETCO2 using theoretical modeling. Pnvf was found to be significantly reduced in CHD patients in default mode network (DMN, comprising the ventromedial prefrontal cortex and posterior cingulate/precuneus), salience network (SN, comprising the insula and dorsal anterior cingulate), and central executive network (CEN, comprising posterior parietal and dorsolateral prefrontal cortex) regions with similar findings noted in single cardiac ventricle patients. Positive correlations of Pnvf in these brain regions, as well as the hippocampus, were found with neurocognitive outcomes. Similarly, positive correlations between Pnvf and nitric oxide availability were found in frontal DMN and CEN regions, with particularly strong correlations in subcortical regions (putamen). Reduced Pnvf in CHD patients was found to be mediated by nNO. Mediation analyses further supported that reduced Pnvf in these regions underlies worse neurocognitive outcome in CHD patients and is associated with nitric oxide bioavailability. Impaired neuro-vascular function, which may be non-invasively estimated via combined arterial-spin label and BOLD MR imaging, is a nitric oxide bioavailability dependent factor implicated in adverse neurocognitive outcomes in pediatric and young adult CHD.

Harmonization of Multi-Center Diffusion Tensor Tractography in Neonates with Congenital Heart Disease: Optimizing Post-Processing and Application of ComBat

Advanced brain imaging of neonatal macrostructure and microstructure, which has prognosticating importance, is more frequently being incorporated into multi-center trials of neonatal neuroprotection. Multicenter neuroimaging studies, designed to overcome small sample sized clinical cohorts, are essential but lead to increased technical variability. Few harmonization techniques have been developed for neonatal brain microstructural (diffusion tensor) analysis. The work presented here aims to remedy two common problems that exist with the current state of the art approaches: 1) variance in scanner and protocol in data collection can limit the researcher's ability to harmonize data acquired under different conditions or using different clinical populations. 2) The general lack of objective guidelines for dealing with anatomically abnormal anatomy and pathology. Often, subjects are excluded due to subjective criteria, or due to pathology that could be informative to the final analysis, leading to the loss of reproducibility and statistical power. This proves to be a barrier in the analysis of large multi-center studies and is a particularly salient problem given the relative scarcity of neonatal imaging data. We provide an objective, data-driven, and semi-automated neonatal processing pipeline designed to harmonize compartmentalized variant data acquired under different parameters. This is done by first implementing a search space reduction step of extracting the along-tract diffusivity values along each tract of interest, rather than performing whole-brain harmonization. This is followed by a data-driven outlier detection step, with the purpose of removing unwanted noise and outliers from the final harmonization. We then use an empirical Bayes harmonization algorithm performed at the along-tract level, with the output being a lower dimensional space but still spatially informative. After applying our pipeline to this large multi-site dataset of neonates and infants with congenital heart disease (n= 398 subjects recruited across 4 centers, with a total of n=763 MRI pre-operative/post-operative time points), we show that infants with single ventricle cardiac physiology demonstrate greater white matter microstructural alterations compared to infants with bi-ventricular heart disease, supporting what has previously been shown in literature. Our method is an open-source pipeline for delineating white matter tracts in subject space but provides the necessary modular components for performing atlas space analysis. As such, we validate and introduce Diffusion Imaging of Neonates by Group Organization (DINGO), a high-level, semi-automated framework that can facilitate harmonization of subject-space tractography generated from diffusion tensor imaging acquired across varying scanners, institutions, and clinical populations. Datasets acquired using varying protocols or cohorts are compartmentalized into subsets, where a cohort-specific template is generated, allowing for the propagation of the tractography mask set with higher spatial specificity. Taken together, this pipeline can reduce multi-scanner technical variability which can confound important biological variability in relation to neonatal brain microstructure.

Cerebellar and Prefrontal Structures Associated With Executive Functioning in Pediatric Patients With Congenital Heart Defects

Objective

Children, adolescents, and young adults with congenital heart defects (CHD) often display executive dysfunction. We consider the prefrontal and cerebellar brain structures as mechanisms for executive dysfunction among those with CHD.

Methods

55 participants with CHD (M age = 13.93) and 95 healthy controls (M age = 13.13) completed magnetic resonance imaging (MRI) of the brain, from which we extracted volumetric data on prefrontal and cerebellar regions. Participants also completed neuropsychological tests of executive functioning; their parents completed ratings of their executive functions.

Results

Compared to healthy controls, those with CHD had smaller cerebellums and lateral, medial, and orbital prefrontal regions, they performed more poorly on tests of working memory, inhibitory control, and mental flexibility, and their parents rated them as having poorer executive functions across several indices. Across both groups, there were significant correlations for cerebellar and/or prefrontal volumes with cognitive assessments of working memory, mental flexibility, and inhibitory control and with parent-completed ratings of task initiation, working memory, and planning/organization. Greater prefrontal volumes were associated with better working memory, among those with larger cerebellums (with group differences based on the measure and the prefrontal region). Greater prefrontal volumes were related to better emotional regulation only among participants with CHD with smaller cerebellar volumes, and with poorer inhibition and emotional regulation only among healthy controls with larger cerebellar volumes.

Conclusion

The cerebellum not only contributes to executive functioning among young individuals with CHD but may also modulate the relationships between prefrontal regions and executive functioning differently for pediatric patients with CHD vs. health controls.

Relationships Between Regional Cerebral Blood Flow and Neurocognitive Outcomes in Children and Adolescents With Congenital Heart Disease

To identify regional cerebral blood flow (rCBF) alterations in children and adolescents with congenital heart disease (CHD) in relation to neurocognitive outcomes using a nonbiased data-driven approach. This is a prospective, observational study of children and adolescents with CHD without brain injury and healthy controls using pseudo-continuous arterial spin labeling (pCASL) MRI. Quantitative rCBF was compared between participants with CHD and healthy controls using a voxelwise data-driven method. Mediation analysis was then performed on a voxelwise basis, with the grouping variable as the independent variable, neurocognitive outcomes (from the NIH Toolbox Cognitive Battery) as the dependent variables, and rCBF as the mediator. After motion correction, a total of 80 studies were analyzable (27 for patients with CHD, 53 for controls). We found steeper age-related decline in rCBF among those with CHD compared to normal controls in the insula/ventromedial prefrontal regions (salience network) and the dorsal anterior cingulate and precuneus/posterior cingulate (default mode network), and posterior parietal/dorsolateral prefrontal (central executive network) (FWE-corrected P< 0.05). The reduced rCBF in the default mode/salience network was found to mediate poorer performance on an index of crystallized cognition from the NIH Toolbox Cognitive Battery in those with CHD compared to controls. In contrast, reduced rCBF in the central executive network/salience network mediated reduced deficits in fluid cognition among patients with CHD compared to controls. Regional cerebral blood flow alterations mediate domain-specific differences in cognitive performance in children and adolescents with CHD compared to healthy controls, independent of injury, and are likely related to brain and cognitive reserve mechanisms. Further research is needed to evaluate the potential of interventions in CHD targeting regional cerebral blood flow across lifespan.

Limbic white matter structural integrity at 3 months prospectively predicts negative emotionality in 9-month-old infants: a preliminary study

BACKGROUND

Little is known about how early alterations in white matter relate to clinically relevant behaviors such as emotional dysregulation. Thus, our goal was to examine how the white matter structural integrity of key limbic (i.e., uncinate fasciculus and cingulum) and commissural (i.e., forceps minor) bundles in 3-month-old infants prospectively predicts emotional regulation behaviors at 9 months.

METHODS

Three-month-old infants underwent multishell diffusion-weighted imaging. Following image processing, tractography was performed for each tract within each infant's native space (n=20). Measures of white matter integrity, including microstructure and morphology, were extracted from each tract. At 9 months, negative emotionality (NE) and positive emotionality (PE) were elicited using Laboratory Assessment of Temperament tasks. Elastic net regressions were performed for variable selection, which included white matter integrity variables from each of the 3 tracts, along with several covariates, including age, sex, use of public assistance, and the mother's depressive symptoms. Outcome variables were NE and PE composite scores evaluated in two separate models.

RESULTS

Notably, following hierarchical regression using elastic net-selected variables, uncinate structural integrity was the most robust predictor of NE (ß=-0.631, p=0.005).

LIMITATIONS

The sample size of our study is a limitation, however, as a preliminary study, our goal was to describe our findings to inform future, larger studies.

CONCLUSIONS

Greater uncinate structural integrity predicted lower NE, suggesting that greater uncinate structural integrity at 3 months allows greater emotional regulation capacity at 9 months. To our knowledge, this is the first study to demonstrate prospective brain-to-emotional behavior relationships in infants.

Feasibility of Implementing Chronic Care Model in the Malaysian Public Primary Care Setting

INTRODUCTION

Non-communicable diseases (NCD) is a global health threat. the Chronic Care Model (CCM) was proven effective in improving NCD management and outcomes in developed countries. Evidence from developing countries including Malaysia is limited and feasibility of CCM implementation has not been assessed. this study intends to assess the feasibility of public primary health care clinics (PHC) in providing care according to the CCM.

METHODOLOGY

A cross-sectional survey was conducted to assess the public PHC ability to implement the components of CCM. All public PHC with Family Medicine Specialist in Selangor and Kuala Lumpur were invited to participate. A site feasibility questionnaire was distributed to collect site investigator and clinic information as well as delivery of care for diabetes and hypertension.

RESULTS

there were a total of 34 public PHC invited to participate with a response rate of 100%. there were 20 urban and 14 suburban clinics. the average number of patients seen per day ranged between 250-1000 patients. the clinic has a good mix of multidisciplinary team members. All clinics had a diabetic registry and 73.5% had a hypertensive registry. 23.5% had a dedicated diabetes and 26.5% had a dedicated hypertension clinic with most clinic implementing integrated care of acute and NCD cases.

DISCUSSION

the implementation of the essential components of CCM is feasible in public PHCs, despite various constraints. Although variations in delivery of care exists, majority of the clinics have adequate staff that were willing to be trained and are committed to improving patient care.

Short-T2 imaging for quantifying concentration of sodium (23 Na) of bi-exponential T2 relaxation

PURPOSE

This work intends to demonstrate a new method for quantifying concentration of sodium (²³ Na) of bi-exponential T₂ relaxation in patients on MRI scanners at 3.0 Tesla.

THEORY AND METHODS

Two single-quantum (SQ) sodium images acquired at very-short and short echo times (TE = 0.5 and 5.0 ms) are subtracted to produce an image of the short-T₂ component of the bi-exponential (or bound) sodium. An integrated calibration on the SQ and short-T₂ images quantifies both total and bound sodium concentrations. Numerical models were used to evaluate signal response of the proposed method to the short-T₂ components. MRI scans on agar phantoms and brain tumor patients were performed to assess accuracy and performance of the proposed method, in comparison with a conventional method of triple-quantum filtering.

RESULTS

A good linear relation (R²  = 0.98) was attained between the short-T₂ image intensity and concentration of bound sodium. A reduced total scan time of 22 min was achieved under the SAR restriction for human studies in quantifying both total and bound sodium concentrations.

CONCLUSION

The proposed method is feasible for quantifying bound sodium concentration in routine clinical settings at 3.0 Tesla. Magn Reson Med 74:162-174, 2015. © 2014 Wiley Periodicals, Inc.

Successful tactile based visual sensory substitution use functions independently of visual pathway integrity

PURPOSE

Neuronal reorganization after blindness is of critical interest because it has implications for the rational prescription of artificial vision devices. The purpose of this study was to distinguish the microstructural differences between perinatally blind (PB), acquired blind (AB), and normally sighted controls (SCs) and relate these differences to performance on functional tasks using a sensory substitution device (BrainPort).

METHODS

We enrolled 52 subjects (PB n = 11; AB n = 35; SC n = 6). All subjects spent 15 h undergoing BrainPort device training. Outcomes of light perception, motion, direction, temporal resolution, grating, and acuity were tested at baseline and after training. Twenty-six of the subjects were scanned with a three Tesla MRI scanner for diffusion tensor imaging (DTI), and with a positron emission tomography (PET) scanner for mapping regional brain glucose consumption during sensory substitution function. Non-parametric models were used to analyze fractional anisotropy (FA; a DTI measure of microstructural integrity) of the brain via region-of-interest (ROI) analysis and tract-based spatial statistics (TBSS).

RESULTS

At baseline, all subjects performed all tasks at chance level. After training, light perception, time resolution, location and grating acuity tasks improved significantly for all subject groups. ROI and TBSS analyses of FA maps show areas of statistically significant differences (p ≤ 0.025) in the bilateral optic radiations and some visual association connections between all three groups. No relationship was found between FA and functional performance with the BrainPort.

DISCUSSION

All subjects showed performance improvements using the BrainPort irrespective of nature and duration of blindness. Definite brain areas with significant microstructural integrity changes exist among PB, AB, and NC, and these variations are most pronounced in the visual pathways. However, the use of sensory substitution devices is feasible irrespective of microstructural integrity of the primary visual pathways between the eye and the brain. Therefore, tongue based devices devices may be usable for a broad array of non-sighted patients.

Combined imaging biomarkers for therapy evaluation in glioblastoma multiforme: correlating sodium MRI and F-18 FLT PET on a voxel-wise basis

We evaluate novel magnetic resonance imaging (MRI) and positron emission tomography (PET) quantitative imaging biomarkers and associated multimodality, serial-time-point analysis methodologies, with the ultimate aim of providing clinically feasible, predictive measures for early assessment of response to cancer therapy. A focus of this work is method development and an investigation of the relationship between the information content of the two modalities. Imaging studies were conducted on subjects who were enrolled in glioblastoma multiforme (GBM) therapeutic clinical trials. Data were acquired, analyzed and displayed using methods that could be adapted for clinical use. Subjects underwent dynamic [(18)F]fluorothymidine (F-18 FLT) PET, sodium ((23)Na) MRI and 3-T structural MRI scans at baseline (before initiation of therapy), at an early time point after beginning therapy and at a late follow-up time point after therapy. Sodium MRI and F-18 FLT PET images were registered to the structural MRI. F-18 FLT PET tracer distribution volumes and sodium MRI concentrations were calculated on a voxel-wise basis to address the heterogeneity of tumor physiology. Changes in, and differences between, these quantities as a function of scan timing were tracked. While both modalities independently show a change in tissue status as a function of scan time point, results illustrate that the two modalities may provide complementary information regarding tumor progression and response. Additionally, tumor status changes were found to vary in different regions of tumor. The degree to which these methods are useful for GBM therapy response assessment and particularly for differentiating true progression from pseudoprogression requires additional patient data and correlation of these imaging biomarker changes with clinical outcome.

"Rhabdoid meningioma" lacking malignant features. Report of two cases

We report 2 cases of meningiomas with rhabdoid morphology but lacking histological features of malignancy. Both occurred in adult women, one arising from the superior surface of the tentorium and the other in the Sylvian fissure. The tumors showed light microscopic, immunohistochemical and ultrastructural evidence of meningothelial differentiation together with diffuse or focal areas exhibiting rhabdoid morphology. The rhabdoid areas were characterized by cells with large cytoplasmic eosinophilic inclusions and large eccentric nuclei. Both cases showed areas with sheet-like growth and one had macronucleoli and brain invasion. The same case showed areas of necrosis that most likely related to pre-operative arterial embolization. Unlike most cases reported in the literature, these "rhabdoid meningiomas" lacked significant mitotic activity or other atypical features. The diagnostic and prognostic significance of this tumor entity is discussed along with a review of the literature.

Herpes zoster and postherpetic neuralgia in the elderly

This article describes herpes zoster (HZ), its cause, diagnosis, treatment, and associated complications. Postherpetic neuralgia (PHN), the most common complication of HZ, is the primary focus of the discussion. PHN is defined broadly as chronic pain that persists after the characteristic vesicular rash of HZ has resolved.

Clinical and radiological aspects in Melnick-Needles syndrome

Melnick-Needles syndrome is an X-linked dominant bone dysplasia, lethal in males, characterized by a typical facies and characteristic radiological findings: including sclerosis of skull base and mastoids. S-shaped appearance of tibia; cortical irregularities with a ribbon appearance of the ribs. About 48 well-documented cases have been reported, most of them were sporadic. Parental transmission has been published in only 11 kindreds. We are presenting the first Brazilian family with mother-daughter transmission. The proposita presented the typical clinical and radiological features with characteristic facies, severe thoracic cage restriction and pulmonary hypertension. Her mother was more mildly affected.

A case report: special needs of hospitalized elders

A case report is used to discuss common problems and complications of hospitalized elders. The report also illustrates the need for proactive hospital staff who are knowledgeable about the special needs of the aging population if this group is to be cared for successfully. The geriatric resource nurse model involves informal unit-based education aimed at expanding staff nurses' geriatric knowledge and is one of several models sponsored by the Hartford Foundation to improve care of the hospitalized elderly. Teaching rounds between geriatric resource nurses and advanced practice nurses are a primary feature of this model.

The hemochromatosis gene product complexes with the transferrin receptor and lowers its affinity for ligand binding

We recently reported the positional cloning of a candidate gene for hereditary hemochromatosis called HFE. The gene product, a member of the major histocompatibility complex class I-like family, was found to have a mutation, Cys-282 --> Tyr (C282Y), in 85% of patient chromosomes. This mutation eliminates the ability of HFE to associate with beta2-microglobulin (beta2m) and prevents cell-surface expression. A second mutation that has no effect on beta2m association, H63D, was found in eight out of nine patients heterozygous for the C282Y mutant. In this report, we demonstrate in cultured 293 cells overexpressing wild-type or mutant HFE proteins that both the wild-type and H63D HFE proteins form stable complexes with the transferrin receptor (TfR). The C282Y mutation nearly completely prevents the association of the mutant HFE protein with the TfR. Studies on cell-associated transferrin at 37 degrees C suggest that the overexpressed wild-type HFE protein decreases the affinity of the TfR for transferrin. The overexpressed H63D protein does not have this effect, providing the first direct evidence for a functional consequence of the H63D mutation. Addition of soluble wild-type HFE/beta2m heterodimers to cultured cells also decreased the apparent affinity of the TfR for its ligand under steady-state conditions, both in 293 cells and in HeLa cells. Furthermore, at 4 degrees C, the added soluble complex of HFE/beta2m inhibited binding of transferrin to HeLa cell TfR in a concentration-dependent manner. Scatchard plots of these data indicate that the added heterodimer substantially reduced the affinity of TfR for transferrin. These results establish a molecular link between HFE and a key protein involved in iron transport, the TfR, and raise the possibility that alterations in this regulatory mechanism may play a role in the pathogenesis of hereditary hemochromatosis.

The hemochromatosis founder mutation in HLA-H disrupts beta2-microglobulin interaction and cell surface expression

We recently reported the positional cloning of a candidate gene for hereditary hemochromatosis (HH), called HLA-H, which is a novel member of the major histocompatibility complex class I family. A mutation in this gene, cysteine 282 --> tyrosine (C282Y), was found to be present in 83% of HH patient DNAs, while a second variant, histidine 63 --> aspartate (H63D), was enriched in patients heterozygous for C282Y. The functional relevance of either mutation has not been described. Co-immunoprecipitation studies of cell lysates from human embryonic kidney cells transfected with wild-type or mutant HLA-H cDNA demonstrate that wild-type HLA-H binds beta2-microglobulin and that the C282Y mutation, but not the H63D mutation, completely abrogates this interaction. Immunofluorescence labeling and subcellular fractionations demonstrate that while the wild-type and H63D HLA-H proteins are expressed on the cell surface, the C282Y mutant protein is localized exclusively intracellularly. This report describes the first functional significance of the C282Y mutation by suggesting that an abnormality in protein trafficking and/or cell-surface expression of HLA-H leads to HH disease.

A 1.1-Mb transcript map of the hereditary hemochromatosis locus

In the process of positionally cloning a candidate gene responsible for hereditary hemochromatosis (HH), we constructed a 1.1-Mb transcript map of the region of human chromosome 6p that lies 4.5 Mb telomeric to HLA-A. A combination of three gene-finding techniques, direct cDNA selection, exon trapping, and sample sequencing, were used initially for a saturation screening of the 1.1-Mb region for expressed sequence fragments. As genetic analysis further narrowed the HH candidate locus, we sequenced completely 0.25 Mb of genomic DNA as a final measure to identify all genes. Besides the novel MHC class 1-like HH candidate gene HLA-H, we identified a family of five butyrophilin-related sequences, two genes with structural similarity to a type 1 sodium phosphate transporter, 12 novel histone genes, and a gene we named RoRet based on its strong similarity to the 52-kD Ro/SSA lupus and Sjogren's syndrome auto-antigen and the RET finger protein. Several members of the butyrophilin family and the RoRet gene share an exon of common evolutionary origin called B30-2. The B30-2 exon was originally isolated from the HLA class 1 region, yet has apparently "shuffled" into several genes along the chromosome telomeric to the MHC. The conservation of the B30-2 exon in several novel genes and the previously described amino acid homology of HLA-H to MHC class 1 molecules provide further support that this gene-rich region of 6p21.3 is related to the MHC. Finally, we performed an analysis of the four approaches for gene finding and conclude that direct selection provides the most effective probes for cDNA screening, and that as much as 30% of ESTs in this 1.1-Mb region may be derived from noncoding genomic DNA.

A novel MHC class I-like gene is mutated in patients with hereditary haemochromatosis

Hereditary haemochromatosis (HH), which affects some 1 in 400 and has an estimated carrier frequency of 1 in 10 individuals of Northern European descent, results in multi-organ dysfunction caused by increased iron deposition, and is treatable if detected early. Using linkage-disequilibrium and full haplotype analysis, we have identified a 250-kilobase region more than 3 megabases telomeric of the major histocompatibility complex (MHC) that is identical-by-descent in 85% of patient chromosomes. Within this region, we have identified a gene related to the MHC class I family, termed HLA-H, containing two missense alterations. One of these is predicted to inactivate this class of proteins and was found homozygous in 83% of 178 patients. A role of this gene in haemochromatosis is supported by the frequency and nature of the major mutation and prior studies implicating MHC class I-like proteins in iron metabolism.

Psychological effects of severe burn injuries

Severe burn injuries provide researchers with an opportunity to study the effects of painful but usually transient trauma on psychological functioning. To that end, this article presents a review of the 3 main areas of this body of literature: (a) premorbid characteristics of people who sustain severe burn injuries, (b) psychological reactions during hospitalization, and (c) long-term adjustment. The general implications of these studies are discussed and then used to illuminate the circumstances under which individuals suffer the most from this type of trauma, the effects of such injuries on personality function, and how meaningful units of measurements can be defined. Potential clinical applications are also described.

T cells from tumor-immune mice nonspecifically expanded in vitro with anti-CD3 plus IL-2 retain specific function in vitro and can eradicate disseminated leukemia in vivo

The therapeutic efficacy of adoptive immunotherapy of cancer has been shown to positively correlate with the dose of tumor-immune T cells transferred. Therefore, the success of this therapy is critically dependent on the ability to procure large numbers of functionally active T cells. Previous studies in animal models have shown that the limited therapeutic efficacy of a small number of immune T cells can be greatly enhanced by expansion of T cells in vitro to greater numbers before transfer in vivo. Optimal regimens for T cell expansion in vitro have generally employed the use of intermittent stimulation of the TCR with specific Ag followed by exogenous IL-2. The use of IL-2 alone does not provide for requisite episodic up-regulation of IL-2R. Stimulation of the invariant CD3 portion of the TCR/CD3 complex with antibody to CD3 (anti-CD3) represents an alternative method of up-regulating IL-2R and has been used to nonspecifically induce the growth of Ag-specific T cell lines and clones long-term in vitro with maintenance of function and specificity. The current study examined whether resting T cell populations containing small numbers of memory tumor-specific T cells could be rendered more effective in tumor therapy by nonspecific expansion in vitro with anti-CD3 plus IL-2. Spleens from C57BL/6 mice previously immunized to FBL-3, a syngeneic virus-induced leukemia, were nonspecifically stimulated with anti-CD3 plus IL-2. The resultant T cells were expanded in number, were nonlytic to FBL-3 but retained the ability to become lytic upon specific stimulation by FBL-3, and were effective in specific tumor therapy. The Ag-specific anti-tumor immune function declined on a per cell basis after each cycle of anti-CD3-induced T cell expansion. However, the approach resulted in a substantial increase in total T cell number and an overall net increase in the function of the effector T cell population. Thus, stimulation of tumor-immune T cell populations with anti-CD3 plus IL-2 represents a nonspecific method for expanding the number of specific effector T cells for cancer therapy.

T cells from tumor-immune mice nonspecifically expanded in vitro with anti-CD3 plus IL-2 retain specific function in vitro and can eradicate disseminated leukemia in vivo

The therapeutic efficacy of adoptive immunotherapy of cancer has been shown to positively correlate with the dose of tumor-immune T cells transferred. Therefore, the success of this therapy is critically dependent on the ability to procure large numbers of functionally active T cells. Previous studies in animal models have shown that the limited therapeutic efficacy of a small number of immune T cells can be greatly enhanced by expansion of T cells in vitro to greater numbers before transfer in vivo. Optimal regimens for T cell expansion in vitro have generally employed the use of intermittent stimulation of the TCR with specific Ag followed by exogenous IL-2. The use of IL-2 alone does not provide for requisite episodic up-regulation of IL-2R. Stimulation of the invariant CD3 portion of the TCR/CD3 complex with antibody to CD3 (anti-CD3) represents an alternative method of up-regulating IL-2R and has been used to nonspecifically induce the growth of Ag-specific T cell lines and clones long-term in vitro with maintenance of function and specificity. The current study examined whether resting T cell populations containing small numbers of memory tumor-specific T cells could be rendered more effective in tumor therapy by nonspecific expansion in vitro with anti-CD3 plus IL-2. Spleens from C57BL/6 mice previously immunized to FBL-3, a syngeneic virus-induced leukemia, were nonspecifically stimulated with anti-CD3 plus IL-2. The resultant T cells were expanded in number, were nonlytic to FBL-3 but retained the ability to become lytic upon specific stimulation by FBL-3, and were effective in specific tumor therapy. The Ag-specific anti-tumor immune function declined on a per cell basis after each cycle of anti-CD3-induced T cell expansion. However, the approach resulted in a substantial increase in total T cell number and an overall net increase in the function of the effector T cell population. Thus, stimulation of tumor-immune T cell populations with anti-CD3 plus IL-2 represents a nonspecific method for expanding the number of specific effector T cells for cancer therapy.

Language changes and Alzheimer's disease: a literature review

1. In Alzheimer's disease, the effect of cognitive changes on language and the ability to communicate and interact with others is profound. 2. Communication difficulties are a common problem identified by caregivers of demented individuals. Breakdown of communication can be frustrating and overwhelming for both patient and caregiver. 3. The deterioration of different linguistic features of language occurs at different rates, making it harder to identify deficits in the early phases of the disease. Mental status testing can give some objective measure of deficits. 4. Research is identifying explicit changes that occur in the language of Alzheimer's disease victims. Knowledge of these changes suggests strategies that can enhance communication.

Tumor-specific idiotopes on suppressor factors and suppressor cells revealed by monoclonal anti-idiotope antibodies

Two monoclonal anti-idiotope antibodies, previously found to induce tumor-specific cell-mediated immunity in mice, were examined for their relationship to tumor-associated suppressor factors (SF), produced in culture by spleen cells from tumor-bearing mice or present in sera from such mice. A leukocyte adherence inhibition assay was used to detect cellular immunoreactivity to tumor antigens and its inhibition by SF, using peritoneal cells from mice bearing tumor or sensitized with anti-idiotope antibody. The SF were specifically absorbed by the corresponding anti-idiotope antibodies coupled to a solid phase and were recovered by elution. They were also specifically neutralized by the addition of the respective antibodies to the assay system. Anti-idiotope antibody, used with complement to pretreat spleen cells from tumor-bearing mice, prevented these cells from producing SF in culture. Tumor antigen-reactive effector cells, suppressor cells, and SF thus share similar idiotopes, permitting their respective functions to be modulated by appropriate anti-idiotopes.

Monoclonal antiidiotypic antibodies related to a murine oncofetal bladder tumor antigen induce specific cell-mediated tumor immunity

Rat monoclonal antibody 6.10 recognizes a 175-kDa protein expressed in all BALB/c mouse transitional cell bladder carcinomas tested, in epithelial cells of the mouse embryo, and in a few epithelial cells of adult mice. The antibody was used as an immunogen to generate two mouse monoclonal antibodies, 21D9 and 43A10, which bind to idiotopes on antibody 6.10 associated with the binding site for the 175-kDa antigen. The antiidiotypic antibodies induced bladder tumor-specific, cell-mediated immunity when injected into syngeneic mice, as shown by delayed-type hypersensitivity reactions in vivo and leukocyte adherence inhibition reactions in vitro. Tumor specificity was demonstrated by employing as controls a chemically induced BALB/c fibrosarcoma, MCA-1511 (MCA, 3-methylcholanthrene), and its corresponding antiidiotypic antibody, 5.96. Lymphocytes from mice sensitized with antibody 21D9 or 5.96 specifically recognized antigens in extracts of BALB/c bladder carcinoma BTCC-1660 (BTCC, bladder transitional cell carcinoma) and sarcoma MCA-1511, respectively, as shown by leukocyte adherence inhibition reactivity. This reactivity was selectively abrogated by prior treatment of the sensitized cells with the appropriate antiidiotypic antibodies and complement. An antigen recognized in vitro by antibody 21D9-sensitized lymphocytes could be separated from BTCC-1660 extract by immunoabsorption with antibody 6.10 and elution with acidic buffer. Our findings indicate that the oncofetal antigen defined by antibody 6.10 is recognized by the immune system of syngeneic mice and suggest that antiidiotypic antibodies related to certain oncofetal antigens can be used to immunize against syngeneic tumors.

Monoclonal antibodies to cell surface antigens shared by chemically induced mouse bladder carcinomas

Rats were immunized with cultured cells from chemically induced transitional cell carcinomas of the mouse urinary bladder, and their spleen cells were hybridized with NS-1 mouse myeloma cells. Following initial screening of antibodies made by hybridoma clones, the tissue distribution of antigens defined by the antibodies was established by using a peroxidase-antiperoxidase technique with frozen sections of a variety of mouse tumors, as well as normal adult and embryonic tissues. Two antibodies were identified which detected antigens with bladder carcinoma specificity. One antibody (3B12) reacted weakly with epithelial cells from several sources, including normal bladder, while the second antibody (6.10), which bound strongly to bladder carcinoma cells, was negative on bladder epithelium and bound (weakly) to only a small fraction of all epithelial cells tested except for epidermal cells and periosteum from embryos. Both antibodies should be useful to assess the immunotherapeutic and immunoprophylactic effects of monoclonal antibodies to tumor-type specific oncofetal antigens.