Filtered Diffusion-Weighted MRI of the Human Cervical Spinal Cord: Feasibility and Application to Traumatic Spinal Cord Injury.

BACKGROUND AND PURPOSE: In traumatic spinal cord injury, DTI is sensitive to injury but is unable to differentiate multiple pathologies. Axonal damage is a central feature of the underlying cord injury, but prominent edema confounds its detection. The purpose of this study was to examine a filtered DWI technique in patients with acute spinal cord injury. MATERIALS AND METHODS: The MR imaging protocol was first evaluated in a cohort of healthy subjects at 3T (n = 3). Subsequently, patients with acute cervical spinal cord injury (n = 8) underwent filtered DWI concurrent with their acute clinical MR imaging examination <24 hours postinjury at 1.5T. DTI was obtained with 25 directions at a b-value of 800 s/mm2. Filtered DWI used spinal cord-optimized diffusion-weighting along 26 directions with a "filter" b-value of 2000 s/mm2 and a "probe" maximum b-value of 1000 s/mm2. Parallel diffusivity metrics obtained from DTI and filtered DWI were compared. RESULTS: The high-strength diffusion-weighting perpendicular to the cord suppressed signals from tissues outside of the spinal cord, including muscle and CSF. The parallel ADC acquired from filtered DWI at the level of injury relative to the most cranial region showed a greater decrease (38.71%) compared with the decrease in axial diffusivity acquired by DTI (17.68%). CONCLUSIONS: The results demonstrated that filtered DWI is feasible in the acute setting of spinal cord injury and reveals spinal cord diffusion characteristics not evident with conventional DTI.

Adverse childhood experiences and substance misuse in young people in India: results from the multisite cVEDA cohort.

BACKGROUND: Adverse childhood experiences (ACEs) increases vulnerability to externalising disorders such as substance misuse. The study aims to determine the prevalence of ACEs and its association with substance misuse. METHODS: Data from the Consortium on Vulnerability to Externalising Disorders and Addictions (cVEDA) in India was used (n = 9010). ACEs were evaluated using the World Health Organisation (WHO) Adverse Childhood Experiences International Questionnaire whilst substance misuse was assessed using the WHO Alcohol, Smoking and Substance Involvement Screening Test. A random-effects, two-stage individual patient data meta-analysis explained the associations between ACEs and substance misuse with adjustments for confounders such as sex and family structure. RESULTS: 1 in 2 participants reported child maltreatment ACEs and family level ACEs. Except for sexual abuse, males report more of every individual childhood adversity and are more likely to report misusing substances compared with females (87.3% vs. 12.7%). In adolescents, family level ACEs (adj OR 4.2, 95% CI 1.5-11.7) and collective level ACEs (adj OR 6.6, 95% CI 1.4-31.1) show associations with substance misuse whilst in young adults, child level ACEs such as maltreatment show similar strong associations (adj OR 2.0, 95% CI 1.1-3.5). CONCLUSION: ACEs such as abuse and domestic violence are strongly associated with substance misuse, most commonly tobacco, in adolescent and young adult males in India. The results suggest enhancing current ACE resilience programmes and 'trauma-informed' approaches to tackling longer-term impact of ACEs in India. FUNDING: Newton Bhabha Grant jointly funded by the Medical Research Council, UK (MR/N000390/1) and the Indian Council of Medical Research (ICMR/MRC-UK/3/M/2015-NCD-I).

Diffusion tensor imaging and tractography in Brown-Sequard syndrome.

STUDY DESIGN: Case report. OBJECTIVE: To demonstrate the utility of diffusion tensor imaging and tractography in two patients with Brown-Sequard syndrome after penetrating cervical cord injury. SETTING: Milwaukee, WI, USA. METHODS: Two patients, who presented with features of Brown-Sequard syndrome after sustaining stab wounds to the neck, underwent DTI and tractography of the cervical cord within a week of the injury. DTI metrics were measured within the left and right hemicord around the level of injury. Diffusion tensor tractography was performed to visualize the site of injury and injured fiber tracts. RESULTS: Axial fractional anisotropy maps at the site of injury showed unilateral damage to the cord structure, and FA was significantly reduced within the injured hemicord in both patients. Tractography allowed for visualization of the injured fiber tracts around the level of injury. Both DTI metrics and tractography showed an asymmetry that corresponded to the neurological deficits exhibited by the patients. CONCLUSION: This report illustrates the utility of DTI and DTT in delineating regions of cord injury in two patients with traumatic Brown-Sequard syndrome. Our results indicate that DTI provides clinically relevant information that supplements conventional MR imaging for patients with acute SCI.

Binge eating and other eating behaviors among patients on treatment for psychoses in India.

OBJECTIVE: 'Medication-induced eating disorder' is implicated as one of the reasons for the weight gain seen in psychotic patients. The aim of this study was to examine the prevalence of binge eating disorder (BED), binge spectrum and other eating behaviors in patients on treatment for non-affective psychoses in India. METHOD: An outpatient cross-sectional study of 73 participants. RESULTS: Most of the binge spectrum behaviors occurred in patients on treatment for more than 2 years and on concomitant antidepressant medication. Patients admitted to obesogenic eating behaviour more readily than actual calorie intake. BED was absent in our sample. CONCLUSION: While binge spectrum eating behaviors were noted in many patients, the absence of BED was striking and could be due to cultural factors. Binge spectrum eating behaviors could be treatment emergent or linked particularly to the improvement from psychoses and post psychotic depression.

Diffusion tensor MR imaging in chronic spinal cord injury.

BACKGROUND AND PURPOSE: Diffusion tensor MR imaging is emerging as an important tool for displaying anatomic changes in the brain after injury or disease but has been less widely applied to disorders of the spinal cord. The aim of this study was to characterize the diffusion properties of the entire human spinal cord in vivo during the chronic stages of spinal cord injury (SCI). These data provide insight into the structural changes that occur as a result of long-term recovery from spinal trauma. MATERIALS AND METHODS: Thirteen neurologically intact subjects and 10 subjects with chronic SCI (>4 years postinjury) were enrolled in this study. A single-shot twice-refocused spin-echo diffusion-weighted echo-planar imaging pulse sequence was used to obtain axial images throughout the entire spinal cord (C1-L1) in <60 minutes. RESULTS: Despite heterogeneity in SCI lesion severity and location, diffusion characteristics of the chronic lesion were significantly elevated compared with those of uninjured controls. Fractional anisotropy was significantly lower at the chronic lesion and appeared dependent on the completeness of the injury. Conversely, mean diffusivity measurements in the upper cervical spinal cord in subjects with SCI were significantly lower than those in controls. These trends suggest that the entire neuraxis may be affected by long-term recovery from spinal trauma. CONCLUSION: These results suggest that diffusion tensor imaging may be useful in the assessment of SCI recovery.

Diffusion tensor MR imaging of the neurologically intact human spinal cord.

BACKGROUND AND PURPOSE: The aim of this study was to characterize the diffusion properties of the entire human spinal cord in vivo. These data are essential for comparisons to pathologic conditions as well as for comparisons of different pulse sequence design parameters aimed to reduce scan time and more accurately determine diffusion coefficients. MATERIALS AND METHODS: A total of 13 neurologically intact subjects were enrolled in this study. A single-shot, twice-refocused, spin-echo, diffusion-weighted, echo-planar imaging (EPI) pulse sequence was used to obtain axial images throughout the entire spinal cord (C1-L1) in 45 minutes. RESULTS: Diffusion images indicated slight geometric distortions; however, gray and white matter contrast was observed. All measurements varied across the length of the cord. Whole cord diffusion coefficients averaged 0.5-1.3 x 10(-3) mm(2)/s depending on orientation, mean diffusivity (MD) averaged 0.83 +/- 0.06 x 10(-3) mm(2)/s, fractional anisotropy (FA) averaged 0.49 +/- 0.05, and volume ratio (VR) averaged 0.73 +/- 0.05. CONCLUSION: This study provided normative diffusion values for the entire spinal cord for use in comparisons with pathologic conditions as well as improvements in pulse sequence design.

Neuroacanthocytosis : a case report.

An adult male with severe tic disorder presented with recurrent injury to tongue and dysphagia. There were a significant excess of acanthocytes in the peripheral blood smear. Treatment with lithium resulted in a considerable reduction in the severity of tics and self-injurious behaviour.

Bioresorbable fixation for congenital pediatric craniofacial surgery: a 2-year follow-up.

We describe our experience with the use of a polymeric biodegradable system for the correction of congenital pediatric craniofacial malformations. These fixation methods present several advantages over conventional metallic fixation systems. Our series consists of 51 patients that underwent craniofacial surgery, 46 for craniosynostosis, and 5 for encephalocele. The mean age of the patients was 3 years (median age 9 months). Patients with coronal or metopic craniosynostosis underwent a bifrontal craniotomy and anterior cranial vault and orbital reconstruction. Three patients with late sagittal synostosis underwent cranial vault reconstruction in two stages. Encephalocele defects were repaired with osteotomies, and/or onlay bone graft. Lactosorb (Lorenz Biomet, Warsaw, Ind.) plates (cut from a prefabricated mesh) and screws were employed using established fixation techniques. Cranial bone was the source of all bone graft when required. Pre- and postoperative clinical, radiographic and photographic examinations were performed on all patients. At 2 years follow-up, no evidence of infection, erythema, extrusion, instability of the bony fragments or relapse has been noted. The plates themselves were universally impalpable by the one year follow-up examination. The results in this series support the use of resorbable fixation systems in the correction of congenital craniofacial deformities.

Posterior fossa craniotomy: an alternative to craniectomy.

We describe a simple midline approach to posterior fossa lesions in children that involves removal and replacement of a bone flap. This approach offers several advantages over conventional suboccipital craniectomy. Elevation of the bone flap is facilitated by the relatively small size of the midline bony keel in children. This method is simple, safe and expeditious, and restores normal anatomical planes and improved protection to the contents of the posterior fossa. While this approach has been described previously for individual cases, the authors employ craniotomy as the standard method of access to the posterior fossa in pediatric patients, and suggest a straightforward technique for removing and replacing the bone flap.

Occurrence of ventricular ectopics in a patient with therapeutic lithium level.

A young male with bipolar affective disorder, mania with psychotic features was started on lithium therapy. Four days later, he developed an irregular pulse on a lithium level of 0.45 mmol/L. An ECG showed multiple unifocal ventricular ectopics. The cardiac arrhythmia disappeared when lithium was discountinued.

Intraarterial O6-benzylguanine enables the specific therapy of nitrosourea-resistant intracranial human glioma xenografts in athymic rats with 1,3-bis(2-chloroethyl)-1-nitrosourea.

The prognosis for patients with malignant gliomas continues to be dismal. The high degree of resistance of gliomas to nitrosourea-based chemotherapy is one major factor in poor treatment outcome. The identification of O6-alkylguanine-DNA alkyltransferase (AGAT) as a major determinant of nitrosourea resistance has resulted in the development of several agents to inactivate this repair protein and counteract tumor cell resistance. However, a major problem in preclinical trials has been the marked nitrosourea dose limitations imposed by the prior administration of AGAT-depleting agents. We investigated the AGAT depletion and selective enhancement of BCNU activity of intraarterial (i.a.) O6-benzylguanine (O6BG) in the human malignant glioma xenograft D-456 MG growing intracranially (i.e.) in athymic rats. Whereas i.a. O6BG at 2.5 mg/kg produced 100% inhibition of D-456 MG AGAT i.e. activity 8 h after administration, intraperitoneal (i.p.) O6BG at this dose produced only 40% inhibition, requiring dose escalation to 10 mg/kg to produce 100% AGAT depletion. Prior administration of i.p. O6BG (10 mg/kg) and i.a. O6BG (2.5 mg/kg) limited maximum tolerated intravenous (i.v.) BCNU doses (37.5 mg/kg when given alone) to 6.25 and 25 mg/kg, respectively. Higher doses of BCNU alone or in combination with O6BG produced histopathologic evidence of cerebral and hepatic toxicity. Therapy experiments revealed a significantly improved median survival for rats treated with O6BG i.a. (2.5 mg/kg) plus BCNU i.v. (25 mg/kg, days 61 and 59 in duplicate experiments) compared with saline (day 21. P = 0.001). O6BG i.a. or i.p. (days 22 and 23, P = 0.001), BCNU i.v. (37.5 mg/kg, day 29, P = 0.001), and O6BG i.p. (10 mg/kg), plus BCNU i.v. (6.25 mg/kg, day 37, P < 0.001). Therefore, O6BG i.a., by virtue of rapid AGAT depletion and selective uptake into i.c. tumors, offers significant potential for regional chemomodulation of AGAT-mediated nitrosourea resistance in malignant human gliomas with concomitant reduction of systemic toxicity.

Tumor antigens in astrocytic gliomas.

Gliomas affect 15,000 to 17,000 Americans every year and carry a dismal prognosis. The potential of immunologically mediated diagnosis and therapy, although greatly enhanced since the advent of monoclonal antibodies, has not been fully realized due to significant problems, most especially the challenge of identifying antigenic molecules specific to glial tumors. Other problematic issues include antigen-associated factors such as heterogeneity, modulation, shedding, and cross-reactivity with normal cells, and factors associated with therapeutic agent delivery, typically variable tumor perfusion and unfavorable diffusional forces in tumor microenvironment. An understanding of these problems called for the delineation of operationally specific antigens (tumor-associated antigens not expressed by the normal central nervous system) combined with the use of compartmental therapeutic approaches to increase the specificity of therapy. Numerous antigens have been identified and are classified as extracellular/matrix-associated, membrane-associated, and intracellular antigens. Nevertheless, only a few have been demonstrated to be of significant therapeutic and diagnostic utility. These few include the extracellular matrix-associated antigens tenascin and GP 240, defined by the monoclonal antibodies 81C6 and Mel-14, both of which are now in Phase I clinical trials, and membrane-associated ganglioside molecules, primarily 3', 6'-isoLD1, defined by the antibody DMAb-22. Recent identification of the overexpression of a deletion variant of the epidermal growth factor receptor (EGFRvIII) in up to 50% of the more malignant glial tumors and the subsequent creation of monoclonal antibodies that are specific to this molecule and do not recognize the wild-type EGFR provide the most exciting development yet in the design of specific antiglioma immunoconjugates. In addition, the tumor-specific nature of EGFRvIII combined with improved knowledge of immune mechanisms, especially in the context of the central nervous system, will facilitate the design of highly selective cell-mediated therapeutic approaches with a view toward obtaining tumor-specific immunity.

Tumor-specific anti-epidermal growth factor receptor variant III monoclonal antibodies: use of the tyramine-cellobiose radioiodination method enhances cellular retention and uptake in tumor xenografts.

Amplification and rearrangement of the epidermal growth factor receptor (EGFR) gene are characteristics of many types of tumors. One class of EGFR mutations, EGFRvIII, is characterized by an in-frame deletion resulting in a truncated external domain of the receptor. EGFRvIII was first identified in a subset of gliomas and has since been found in some non-small cell lung carcinomas and breast carcinomas. mAbs specific for this variant form of EGFR but unreactive with the wild-type EGFR have been reported from our laboratory. This study further characterizes three of these antibodies. We determined, via radiolabeling techniques and immunofluorescence microscopy, that, after cell binding in vitro, the anti-EGFRvIII-specific mAbs internalize at 37 degrees C. Furthermore, subsequent to internalization, the antibodies were processed intracellularly, presumably by lysosomal degradation. We also examined the use of an alternative radiolabeling procedure that uses nonmetabolizable radio-iodinated tyramine cellobiose. Our results show that the tyramine cellobiose labeling method allows for greater tumor cell retention of radiolabel in vitro (76% for tyramine cellobiose and 27% for Iodo-Gen after 24 h). Paired-label biodistribution studies in athymic mice indicate that anti-EGFRvIII mAb L8A4 localizes specifically to EGFRvIII-expressing tumor xenografts with a maximum of 34.3 +/- 7.6% injected dose/g when labeled using tyramine cellobiose compared with a maximum of 14.9 +/- 4.3% injected dose/g using Iodo-Gen; similar results were obtained with mAb H10. These results suggest that the anti-EGFRvIII mAbs may serve as potential carriers for radioconjugate- and immunotoxin-based therapies for tumors expressing EGFRvIII.

Intraarterial administration of melphalan for treatment of intracranial human glioma xenografts in athymic rats.

Malignant gliomas will affect 15,000-17,000 Americans each year and carry a dismal prognosis. Adjuvant chemotherapy is hampered by inadequate drug delivery, systemic toxicity, and a markedly variable biological sensitivity. Intraarterial (i.a.) therapy may enhance selectivity by improving tumor drug delivery and reducing systemic toxicity. Using melphalan given i.a., we studied the therapy of intracranial human glioma xenografts in male athymic nude rats (mean weight, 300 g) which were inoculated intracerebrally with D-54 MG and D-456 MG. On Days 6 and 7 (D-54 MG) or Days 9 and 10 (D-456 MG), rats randomized by body weight and treated with single-dose melphalan given i.a. at 0.5 or 0.75 mg produced significantly higher median survival (D-54 MG, Days 33 and 32; D-456 MG, Days 52 and 54, respectively) compared with i.a. saline (D-54 MG, Day 14, P < 0.001; D-456 MG, Day 24, P = 0.000) or melphalan given i.v. at 0.75 mg and 0.9 mg (D-54 MG only; Day 19, P < 0.001; Day 23, P < 0.001, respectively) and at 0.5 and 0.75 mg (D-456 MG only; Day 26 for both doses, P = 0.00). Although a dose-dependent increase in median survival (D-54 MG, 0.25 mg, Day 18; 0.5 mg, Day 28.5; 0.75 mg, Day 32.5) was observed with i.a. administered melphalan, no significant difference was apparent between 0.5 and 0.75 mg in either tumor model (D-54 MG, P = 0.15; D-456 MG, P = 0.37). Toxicity studies in nontumor-bearing athymic rats yielded a maximum tolerated dose of 0.8 mg for i.a. administered melphalan. This dosage was superior in spite of different xenograft permeabilities (apparent mean blood-to-tissue transport [K] values for alpha-aminoisobutyric acid, 5.8 for D-54 MG and 1.3 for D-456 MG). Pharmacokinetic experiments demonstrated a significant first pass advantage for i.a. (versus i.v.) melphalan. The short plasma half-life, marked antiglioma activity, and lack of requirement for metabolic activation indicate that i.a. melphalan holds considerable promise for human glioma therapy.

Monoclonal antibodies against EGFRvIII are tumor specific and react with breast and lung carcinomas and malignant gliomas.

Despite molecular biological advances in understanding human cancers, translation into therapy has been less forthcoming; targeting neoplastic cells still requires that tumor-specific markers, preferably those on the cell surface, be identified. The epidermal growth factor receptor (EGFR) exists in a deletion-mutant form, EGFRvIII, which has been identified by genetic and immunological means in a subset of gliomas and non-small cell lung carcinomas. Specific polyvalent antisera to the extracellular portion of the variant were readily induced, but immunization using a synthetic linear peptide representing the unique EGFRvIII primary sequence has been unsuccessful in mice or macaques. We report here five specific monoclonal antibodies (mAbs) developed through long-term immunization protocols using the EGFRvIII-specific synthetic peptide and the intact variant in different formats that maintained secondary and tertiary conformation. These mAbs identify the EGFRvIII on the cell surface with relatively high affinity (KA range, 0.13 to 2.5 x 10(9) M-1) by live cell Scatchard analysis. These mAbs are specific for EGFRvIII as determined by RIA, ELISA, Western blot, analytical flow cytometry, autophosphorylation, and immunohistochemistry. Isolating specific mAbs enabled us to analyze normal and neoplastic human tissue and establish that EGFRvIII is truly tumor specific for subsets of breast carcinomas and for previously reported non-small cell lung carcinomas and gliomas. Also, this receptor is not expressed by any normal human tissues thus far examined, including elements of the peripheral, central nervous, and lymphoid systems. With mAbs, we identified a higher incidence of EGFRvIII positivity in gliomas than previously described and identified an EGFRvIII-positive subset of breast tumors; also, we observed that the EGFRvIII epitope is not expressed in normal tissues, and we demonstrated the localizing and therapeutic potential of the mAbs for tumors expressing this epitope. Our observations strongly warrant development of this mAb-antigen system as therapy for breast, lung, and central nervous system tumors.

Investigation of a synthetic peptide as immunogen for a variant epidermal growth factor receptor associated with gliomas.

We have previously demonstrated antibody production to a glioma-associated variant form of the human epidermal growth factor receptor in rabbits that had received a synthetic peptide mimicking the unique primary structure of the variant protein as immunogen. We report here the response of mice, rabbits, goats, and macaques immunized by various protocols to this peptide. Titers to both peptide- and cell-elaborated variant receptor were measured, and the capacity to recognize the variant receptor in human tumor samples was determined. Within the range of species and strains investigated, we demonstrated a variable species-associated response to the peptide (rabbits > mice > goats > rats > macaques). Rabbits and a single goat produced specific, high titer antibody activity to the variant receptor protein following immunization with peptide alone. Murine titers to the parent protein were not appreciable following peptide immunization alone; additional immunization with variant receptor as expressed on cell membranes was used to boost this response.