"Living Well" After Burn Injury: Using Case Reports to Illustrate Significant Contributions From the Burn Model System Research Program

The Burn Model System (BMS) program of research has been funded since 1993 by the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR). The overarching aim of this program is to improve outcomes and quality of life for people with burns in the areas of health and function, employment, and community living and participation. This review reports on BMS contributions that have affected the lives of individuals with a significant burn injury using case reports to associate BMS contributions with recovery. In January 2020, current BMS grantee researchers assessed peer-reviewed BMS publications from 1994 to 2020. Using case report methodology, contributions were linked to three individuals treated at one of the four Burn Model System institutions. With over 25 years of NIDILRR funding, unique BMS contributions to patient recovery were identified and categorized into one of several domains: treatment, assessment measures, sequelae, peer support, employment, and long-term functional outcomes. A second review for significant results of BMS research that add to the understanding of burn injury, pathophysiology, and recovery research was identified and categorized as injury recovery research. The case study participants featured in this review identified select NIDILRR research contributions as having direct, personal benefit to their recovery. The knowledge generation and clinical innovation that this research program has contributed to our collective understanding of recovery after burn injury is considerable. Using case study methodology with three adult burn survivors, we highlight the impact and individual significance of program findings and reinforce the recognition that the value of any clinical research must have relevance to the lives of the study population.

Multiplexed genotyping using a novel digitally inscribed bead-based system

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Background: Genotyping of clinical samples has been limited to low levels of multiplexing, ranging from one to a few dozen single nucleotide polymorphisms (SNPs) per sample. By increasing multiplexing levels, a clinical lab can increase information content per sample, decreasing costs and sample material requirements. Methods: We have adapted the GoldenGate® Assay for simultaneously genotyping 96 to 1,536 SNPs to the BeadXpress™ System, a new high-throughput platform that utilizes digitally inscribed VeraCode™ beads in a compact fluidic instrument. Genotyping on this platform ranges from 96 to 384 multiplexing, using the same GoldenGate Assay that has proven highly robust for millions of genotypes. In preliminary tests, we have observed greater than 99% call rates, and greater than 99.5% rates for reproducibility and heritability. In a test of 96 SNP genotypes chosen for a study of colorectal cancer, a point mutation in the MSH2 gene, previously implicated in predisposition to several cancers, was correctly genotyped when compared to qPCR analysis of the same samples. Conclusion: Together with genotyping data from reference samples, the GoldenGate Assay on the BeadXpress System has yielded highly reproducible and accurate genotypes, suggesting that this approach will prove useful for rapid refinement of SNPs for development of clinical genotyping tests.

No significant financial relationships to disclose.

Corpus callosum damage and interhemispheric transfer of information following closed head injury in children

We evaluated the relationship of corpus callosum atrophy and/or lesions on magnetic resonance imaging (MRI) to functional hemispheric disconnection following closed head injury (CHI) in 51 pediatric patients, including mild CHI, moderate to severe CHI with extracallosal lesions, and moderate to severe CHI with callosal atrophy and/or lesions. Interhemispheric transfer of information was assessed using auditory, motor, tactile, and visual tests in patients and in 16 uninjured children. Total and regional callosal areas were measured from the midsagittal MRI slice by morphometry. The corpus callosum lesion group demonstrated a greater right ear advantage on verbal dichotic listening than all other groups. Areas of the posterior corpus callosum were negatively correlated with laterality indices of verbal dichotic listening performance and tachistoscopic identification of verbal material. The relationship of corpus callosum atrophy and/or lesions to asymmetry in dichotic listening is consistent with previous investigation of posttraumatic hemispheric disconnection effects in adults.

Magnetic resonance angiography of primary varicella vasculitis: report of two cases

Two patients with onset of hemiparesis 3 weeks following primary varicella infection demonstrated contralateral temporal lobe and basal ganglia infarctions on magnetic resonance imaging. In both cases, magnetic resonance angiography (MRA) was performed and demonstrated flow abnormalities ipsilateral to the infarcts. Digital subtraction angiography was performed in one case; however, the findings were significantly less conspicuous than those of the MRA. MRA proved to be sensitive to the diagnosis of varicella-induced vasculitis in two consecutive cases and provided a noninvasive means of following the progression of the disease process in response to therapy.

Capillary hemangioma of the neck: prenatal MR findings

Prenatal MR findings of a case of extracranial capillary hemangioma simulating an encephalocele at sonography are reported. MR imaging had an adjunctive diagnostic role in excluding the possibility of an encephalocele. The capillary hemangioma had diffuse T2 hypointensity prenatally, which is atypical of postnatal imaging findings.

Magnetic resonance imaging in relation to functional outcome of pediatric closed head injury: a test of the Ommaya-Gennarelli model

OBJECTIVE

To characterize late neuropathological findings of pediatric closed head injury (CHI), to assess depth of brain lesion in relation to acute severity, and to assess long-term outcome to test the Ommaya-Gennarelli model.

METHODS

Magnetic resonance imaging (MRI) at least 3 months postinjury in a prospective sample (n 5 169) and at least 3 years after CHI in a retrospective sample (n 5 82) was studied. Lesion volume was measured by planimetry. Acute CHI severity was measured by the Glasgow Coma Scale. Patients were classified according to the depth of the deepest parenchymal lesion into no lesion, subcortical, and deep central gray/brain stem groups. The outcomes were assessed by the Glasgow Outcome Scale and the Vineland Adaptive Behavior Scale, which were performed at the time of the MRI in the retrospective sample and up to 3 years postinjury in the prospective sample.

RESULTS

Focal brain lesions were present in 55.4% of the total sample. Depth of brain lesion was directly related to severity of acute impairment of consciousness and inversely related to outcome, as measured by both the Glasgow Outcome Scale and the Vineland Adaptive Behavior Scale. A rostrocaudal gradient of hemispheric lesion frequency was observed, whereas the posterior lesions of the corpus callosum were particularly common. Total lesion volume could not explain the depth of lesion effect.

CONCLUSION

Our findings extend support for the Ommaya-Gennarelli model to pediatric CHI, indicating that depth of brain lesion is related to functional outcome. The relative frequency of focal brain lesions revealed by late MRI is higher than that of previous findings using acute computed tomography. Future investigations could explore whether depth of lesion observed using late MRI is sensitive to neuroprotective interventions.

Frontal lobe changes after severe diffuse closed head injury in children: a volumetric study of magnetic resonance imaging

In view of the pathophysiology and biomechanics of severe closed head injury (CHI) in children, we postulated that the frontal lobes sustain diffuse injury, even in the absence of focal brain lesions detected by magnetic resonance imaging (MRI). This study quantitated the morphological effects of CHI on the frontal lobes in children who sustained head trauma of varying severity. The MRI findings of 14 children who had sustained severe CHIs (Glasgow Coma Scale score of < or = 8) were compared with the findings in a matched group of 14 children having sustained mild head injuries (Glasgow Coma Scale score of 13-15). The patients ranged in age from 5 to 15 years at the time of their MRIs, which were acquired at least 3 months postinjury. MRI findings revealed no focal areas of abnormal signal in the frontal lobes. Volumetric analysis disclosed that the total prefrontal cerebrospinal fluid increased and the gray matter volume decreased in the patients with severe CHI, relative to the mildly injured comparison group. Gray matter volume was also reduced in the orbitofrontal and dorsolateral regions of the brains of children with severe CHI, relative to the children who sustained mild head trauma. These volumetric findings indicate that prefrontal tissue loss occurs after severe CHI in children, even in the absence of focal brain lesions in this area. Nearly two-thirds of the children who sustained severe CHIs were moderately disabled after an average postinjury interval of 3 years or more, whereas 12 of the 14 patients with mild CHIs attained a good recovery (2 were moderately disabled) by the time of study.(ABSTRACT TRUNCATED AT 250 WORDS)

A tissue-specific enhancer in the rat-calcitonin/CGRP gene is active in both neural and endocrine cell types

The calcitonin gene related peptide (CGRP) gene is a complex transcription unit that is expressed in a highly restricted pattern in both the nervous system, particularly in sensory ganglia and brainstem, and in the thyroid C cells of the endocrine system, with tissue-specific alternative RNA processing events generating transcripts encoding either the hormone, calcitonin, or the neuropeptide, CGRP. This pattern of expression in neural and endocrine tissues raises the question whether similar or distinct genomic elements are responsible for activation in both neural and endocrine cell types. We have identified a complex enhancer element, located more than 1 kilobase 5' of the transcription initiation site of the calcitonin/CGRP gene that functions in cells of neuronal or C cell origin, but not in any other cell type tested. At least two complementary regulatory sequences are required for the function of the cell-specific enhancer.

Evidence for carrier-mediated transport of glucocorticoids by human placental membrane vesicles

Glucocorticoid uptake by isolated placental membrane vesicles has been studied in an attempt to identify a membrane-mediated carrier mechanism. A preliminary communication from this laboratory has reported that uptake of the glucocorticoid corticosterone by these vesicles was a time-dependent, saturable, osmotically sensitive process (Fant, M.E., Harbison, R.D. and Harrison, R.W. (1979) J. Biol. Chem. 254, 6218-6221), but did not conclusively demonstrate a carrier mechanism. Further studies of labeled corticosterone uptake by placental vesicles are described herein which indicate that steroid uptake by these vesicles is a carrier-mediated process. We found that corticosterone uptake was temperature-sensitive, and an apparent phase-transition effect on the rate of uptake was seen to occur at approximately 16 degrees C. Treatment of the vesicles with phospholipase A2 and the sulfhydryl group attacker, p-chloromercuriphenylsulfonate, inhibited corticosterone uptake. In contrast to our previous findings in intact cells, neuraminidase treatment of membranes did not inhibit steroid uptake, perhaps indicating a species variation. Lastly, it was possible to show that corticosterone movement across the membrane exhibited countertransport, a phenomenon common only to carrier-mediated transport mechanisms. These studies show that placental vesicles accumulate corticosterone by a carrier-mediated mechanism.

Evidence for glucocorticoid transport into AtT-20 cells. Selective effect of a sulfhydryl inhibitor on uptake

The purpose of these experiments was to determine if membrane-mediated glucocorticoid uptake by the AtT-20 cell was sensitive to the sulfhydryl group inhibitor, p-chloromercuriphenylsulfonate (PCMPS). This agent was chosen because of its reported limited entry into the cell interior. Our experimentes showed that cells could be incubated with 1 mM PCMPS for 1 h before intracellular concentrations of the inhibitor were sufficient to affect the intracellular cytosol receptor. In contrast less than 15 min of treatment inhibited intact cell steroid uptake. The inhibition was completely reversed by dithiothreitol. These studies show inhibition of glucocorticoid uptake under conditions which do not affect the intracellular receptor and infer that the AtT-20 cell membrane-mediated uptake mechanism for glucocorticoids contains sensitive sulfhydryl groups.

Corticosterone binding in AtT-20 pituitary tumor cell cytosol: evidence for one class of binding site for both natural and synthetic glucocorticoids

The AtT-20 mouse pituitary cell is an established, cloned cell line which produced adrenocorticotrophic hormone in a glucocorticoid-suppressible manner. A receptor for glucocorticoids was identified in cytosol prepared from these cells using the natural mouse glucocorticoid, corticosterone, as the labeled ligand. The question of whether this binding component is identical to the one detectable using labeled triamcinolone acetonide was addressed by comparing their physicochemical characteristics and by detailed studied of binding specificity using both ligands. The corticosterone and triamcinolone acetonide binding components behaved similarly on sucrose density gradient analysis and DEAE-cellulose ion-exchange chromatography. Scatchard analysis with corticosterone detected 30% fewer binding sites than a similar analysis with triamcinolone acetonide, probably because corticosterone binding was of lower affinity (Kd = 8.6 . 10(-9)M vs. 1.4 . 10(-9)M) and hence less stable. The relative glucocorticoid binding affinities of thirteen unlabeled steroids were obtained using either labeled steroid as ligand. Both ligands yielded similar results, suggesting that they both detected a similar binding site. The results suggest that AtT-20 cell cytosol contains a single class of binding site which detects both natural and synthetic glucocorticoids.

Heterogeneity of AtT-20 cell glucocorticoid binding sites: evidence for a membrane receptor

In previous studies we have found that intact AtT-20 cells contained two glucocorticoid binding sites with distinctly different affinities and specificity. In this paper, the nature of these sites was investigated by studying glucocorticoid binding to cytosol and to plasma membranes isolated from AtT-20 mouse pituitary tumor cells. Plasma membrane vesicles were isolated from AtT-20 cells and found to take up alpha-aminoisobutyric acid, indicating that they were properly oriented and functionally intact. Corticosterone bound to these vesicle in a time- and temperature-dependent manner. The binding exhibited a glucocorticoid preference since non-glucocorticoids such as progesterone, testosterone or estradiol were unable to inhibit binding. In addition, binding specificity differed from that of the cytoplasmic receptor since the synthetic glucocorticoids were also ineffective competitors. The major inhibitors of binding were corticosterone greater than 11-dehydrocorticosterone greater than 11-ketoprogesterone greater than cortisol. In other complementary studies, AtT-20 cell cytosol was tested to determine whether heterogenous soluble sites exhibiting a preference for the natural vs the synthetic steroid could also be identified. We found that binding sites for both steroid classes were approximately similar in number, specificity and behavior on ion-exchange chromatography. We conclude that, in addition to a classical soluble cytoplasmic glucocorticoid receptor, AtT-20 cells contain plasma membrane glucocorticoid binding sites. The affinity and specificity of these sites for the natural ligand, corticosterone, suggest that they play an important role in the subcellular mechanism of glucocorticoid action.