Clinical worsening in multiple sclerosis is associated with increased frequency and area of gadopentetate dimeglumine-enhancing magnetic resonance imaging lesions

It is now well established that clinically stable patients with relapsing-remitting multiple sclerosis have ongoing disease activity when evaluated by serial gadolinium-enhanced (Gd-DTPA) magnetic resonance imaging (MRI) scans. Despite this, the relationship between clinical disease and MRI lesions, though suspected, has not been extensively documented. The relationship between Gd-DTPA MRI lesions and clinical disease was examined in this study of 9 patients with mild relapsing-remitting multiple sclerosis (Expanded Disability Status Scale [EDSS] < 3.5) who had 24 to 37 monthly Gd-DTPA MRI scans, neurological examinations, and EDSS score assignments. The area and frequency of Gd-DTPA lesions were examined during months with and without clinical worsening as measured by EDSS. Forty-one episodes of clinical worsening were noted during the study. A significant association was observed between these periods of clinical worsening and MRI parameters, including increases in total number, number of new lesions, and the total area of enhancement. Logistic regression analysis showed a significant effect of the number and area of Gd-DTPA MRI lesions on both the onset and continuation of clinical worsening, confirming an important relationship between clinical disease and an increase in cerebral Gd-DTPA MRI activity. A relationship with long-term disability was suggested, but cannot be confirmed without longer follow-up of these patients.

Decomposition of recognition memory event-related potentials yields target, repetition, and retrieval effects

Task manipulations and a subtractive analytic strategy were combined to decompose the positive-going amplitude shift of the event-related potential (ERP) that is elicited by previously studied words during recognition memory testing. Target stimuli elicited a robust posterior P3b subcomponent, but this effect is shown to be independent of the effects of prior study. Two study-related subcomponents were also identified. The earlier study effect reached peak amplitude about 400 msec after word onset and was elicited by repeated words regardless of whether the task required retrieval of information from secondary memory. This effect might reflect a repetition-related decline in the amplitude of the N400 component. The other study-related effect reached peak amplitude around 600 msec post-stimulus onset. This later effect overlapped temporally with the P3b, but it was not related to targetness. Rather, it was specifically related to task conditions that required retrieval from secondary memory. The identification of this third effect helps to clarify the functional significance of the ERPs observed during recognition memory testing.

Pro-opiomelanocortin neuropeptide receptors on developing and dystrophic muscle fibers

Autoradiography was used to investigate the presence of corticotropin and beta-endorphin receptors on soleus, extensor digitorum longus, and diaphragm muscles of normal and dystrophic adult mice and developing mice. In both adult and developing mice, specific binding sites for both [125I]ACTH and [125I]beta-endorphin were present in some fibers in all of the muscles examined. The specific binding sites appeared to be distributed over the length of the surface membrane in the fibers that expressed them. There were significantly higher proportions of fibers exhibiting the specific beta-endorphin and the specific ACTH binding sites in the three muscle types in mice of 5 d of age compared to the muscles of the normal adult. There was also a higher proportion of fibers with the putative ACTH and beta-endorphin receptors in the three muscle types in dystrophic mice.

Neurophysiological Manifestations of Recollective Experience during Recognition Memory Judgments

Decisions regarding whether an item has been previously encountered are typically accompanied by one of two distinct forms of subjective awareness: either a general sense of familiarity, or conscious recollection of specific details from a prior study episode. To examine the neurophysiological concomitants of these different types of internal experience, event-related potentials (ERPs) were recorded while subjects engaged in a modified recognition memory procedure that required them to describe their subjective response during each testtrial. Stimuli that evoked recollection were accompanied by waveforms distinct from those that evoked only a sense of familiarity, and waveforms for both categories of correctly classified old items differed from correctly rejected distractor items and incorrectly classified (missed) studied items. These ERP responses are interpreted with respect to current knowledge concerning the neural structures and processes intimately involved in the capacity to engage in recollection.

Voice problems after pediatric laryngotracheal reconstruction: videolaryngostroboscopic, acoustic, and perceptual assessment

Children with laryngotracheal stenosis undergo laryngotracheal reconstruction (LTR) to permit tracheostomy decannulation. We conducted voice assessments of 8 pediatric LTR patients with voice problems. Perceptual ratings and acoustic measures were taken in 5 patients and videolaryngoscopy/laryngostroboscopy was conducted in all 8. Results of perceptual evaluation were abnormal for hoarseness, breathiness and pitch. Acoustic analysis revealed a markedly decreased fundamental frequency of phonation, diminished frequency range, decreased vocal intensity, and shortened maximum phonation time. Videolaryngostroboscopic findings are summarized as follows: 2 patients had severe glottal insufficiency, 3 patients had vocal fold asymmetry in stiffness and position, and 3 patients demonstrated phonation using supraglottal structures. Use of the stroboscope contributed to diagnosis in 3 of 8 patients. Reverse (inhalatory) phonation was observed in three patients. Concomitant articulation problems were exhibited frequently. Sentence production was shortened by the decreased phonatory duration. When coupled with the abnormal voice quality, speech intelligibility was significantly affected. Voice problems following decannulation were observed to persist as a long-term difficulty in some LTR patients.

Short echo time proton MR spectroscopic imaging

Proton spectroscopic imaging at short TEs (20-30 ms) in human brain requires volume preselection inside the brain to suppress overwhelming lipid and water signals from surrounding tissue. In this article we discuss limitations of conventional volume preselection using stimulated echoes that lead to spectral contamination from surrounding tissue. Improved volume preselection was obtained by adding a complete outer volume suppression (presaturation). The performance of the method is illustrated on normal volunteers and on clinical cases with brain tumors and multiple sclerosis (MS) plaques. In normal human brain, we detected resonances with short T2 values and complex J-coupling, including rather broad methyl/methylene resonances in the chemical shift range between 0 and 2 ppm. Spectroscopic images obtained on patients with intracranial tumors and on one patient with several MS plaques demonstrate the possibility of detecting regional distributions of increased methyl/methylene resonances between 0 and 2 ppm in brain lesions.

Service utilization patterns as determinants of capitation rates

OBJECTIVE

In a capitation payment system, the ability to project service requirements and cost is critical. The types and levels of services needed by persons with serious mental illness vary. The purpose of this study was to identify different patterns of service utilization and patient characteristics and costs associated with them.

METHODS

Service use by 55 clients participating in a psychosocial-habilitation outpatient program at a hospital-based community mental health center was tracked for one year. Treatment cost for all services was calculated for each patient.

RESULTS

Cluster analysis indicated that for persons with serious mental illness who enter community treatment, there appear to be four distinct patterns of service use: low, moderate, moderately high, and high. The groups were differentiated only by the presence of a disability (among the moderately high users) and a history of frequent inpatient treatment (among the high users). The two highest-use groups represented about one-third of the total sample but consumed more than three-fourths of the total resources.

CONCLUSIONS

The lack of significant group differences on most clinical variables may make it difficult to develop capitation rates for subgroups of persons with serious mental illness. Service use may be determined by factors other than clinical need.

Using gadolinium-enhanced magnetic resonance imaging lesions to monitor disease activity in multiple sclerosis

The highly variable clinical course and the lack of a direct measurement of disease activity have made evaluation of experimental therapies in multiple sclerosis (MS) difficult. Recent studies indicate that clinically silent lesions can be demonstrated by magnetic resonance imaging (MRI) in patients with mild relapsing-remitting MS. Thus, MRI may provide a means for monitoring therapeutic trials in the early phase of MS. We studied 12 patients longitudinally for 12 to 21 months with monthly gadolinium (Gd)-enhanced MRIs. The data have been used to identify the most effective design of a clinical trial using Gd-enhanced lesions as the outcome measure. Frequent ( > 1/mo) Gd-enhancing lesions were observed in 9 of the 12 patients, indicating that the disease is active even during the early phase of the illness. The frequency of the lesions was not constant; there was marked fluctuation in lesion number from month to month. However, the magnitude of the peak number of lesions and the frequency of the peaks varied among patients. Because of this variability, the most effective use of Gd-enhancing lesions as an outcome measure in a clinical trial was a crossover design with study arms of sufficient duration to allow accurate estimation of lesion frequency. Monitoring Gd-enhancing lesions may be an effective tool to assist in the assessment of experimental therapies in early MS.

POMC-derived peptides in the neuromuscular system of streptozotocin-diabetic mice

Immunoreactivity for beta-endorphin and alpha-MSH/ACTH was demonstrated in intramuscular nerves in soleus, extensor digitorum longus, and diaphragm muscles of normal and streptozotocin-diabetic mice. There was a higher incidence of immunoreactive nerves in the muscles of the diabetic mice. Specific binding for [125I]ACTH was detected in a proportion of the muscle fibers, using autoradiography. There were significantly more fibers with specific [125I]beta-endorphin sites and specific [125]ACTH sites in some muscles in the diabetic mice. The increased expression of POMC-derived peptides and their receptors in the neuromuscular system of streptozotocin-diabetic mice may indicate early neuropathic change.

Phonation and swallowing considerations in pediatric laryngotracheal reconstruction

Experience with laryngotracheal reconstruction (LTR) has resulted in and continues to yield modifications and refinements in approach and technique with the goal to restore and maintain total laryngeal function. In addition to airway obstruction, the laryngeal functions of phonation and swallowing also may be affected by the underlying injury as well as by procedures designed to enlarge the airway. This paper discusses various problems encountered with phonation and swallowing in pediatric patients who underwent LTR and postoperative patients who were seen during the year July 1, 1990, through June 30, 1991. Phonation problems became apparent as long-term difficulties that persisted after tracheotomy decannulation. Swallowing was frequently a short-term perioperative problem while a stent was in place following LTR. The approaches and techniques that have been employed to treat, minimize, and prevent these problems are discussed.

Resource-limited information processing in alcoholism

A concurrent-task paradigm was utilized to examine the availability of limited-capacity information-processing resources in long-term chronic alcoholism. Normal control subjects and detoxified long-term alcoholics did not differ in their performance of a primary task that required an assessment of the meaning of foveally-presented words. However, reaction time measures indicated that the abstinent alcoholics were relatively impaired in their ability to concurrently perform a secondary task that required them to detect randomly-occurring and spatially-distributed visual probe stimuli. This impairment is interpreted as reflecting an abnormal limitation in the attentional resources abstinent alcoholics have available for task performance. The relationship between this deficit and the types of biological abnormalities and neuropsychological impairments commonly observed in alcoholism is discussed.

The binding of human alloantibodies to recombinant glycophorin A

Chinese hamster ovary (CHO) cells were transfected with the wild-type, M allele of glycophorin A cDNA. The binding of human alloantibodies to recombinant glycophorin A was assessed with a modified hemagglutination-inhibition assay. Patient sera were incubated with acetone powders derived from CHO cells, and the adsorbed supernatants were tested in standard hemagglutination assays. Five M antibodies and one sample containing anti-En(a) bound to transfected CHO cells expressing glycophorin A but did not bind to untransfected CHO cells. Three N antibodies as well as 21 other alloantibodies (representing other major red cell blood group specificities) bound to neither CHO cell line. The M allele specificity of recombinant glycophorin A was further verified by the demonstration that a high-titer D alloantibody maintained the same titer of agglutination after incubation with recombinant glycophorin A. Transfected CHO cells thus express an M blood group antigen that appears to be serologically equivalent to that found on human red cells. A panel of cell lines expressing mutant glycophorin A molecules with defined variations in amino acid sequence and carbohydrate composition will be useful in studies of the fine specificity of human glycophorin alloantibodies. This approach may also provide an abundant source of artificial antigens for clinical use in blood group serology.

Effect of IDPN on the expression of POMC-derived peptides in rat motoneurones

Immunocytochemistry was used to detect beta-endorphin and alpha-melanotropin (alpha-MSH) in lumbar spinal motoneurones in rats treated with beta,beta'-iminodiproprionitrile (IDPN), a neurotoxicant that targets motoneurones or corn oil, which has no known neurotoxicity. After IDPN treatment most of the motoneurones were immunoreactive for both peptides but after corn oil treatment immunostaining was negligible. It is suggested that increased expression of the POMC-derived peptides may be part of the regenerative repertoire of the damaged motoneurone regardless of the cause of the lesion. Alternatively the peptides may simply accumulate in the motoneurones as a result of impaired axoplasmic transport.

Reactivation of latent herpes simplex virus by excimer laser photokeratectomy

We tested whether excimer laser photorefractive and phototherapeutic keratectomy may reactivate latent herpes simplex and cause recurrent keratitis in mice. Two of ten latently infected mice that were treated with ten excimer laser pulses to the corneal epithelium shed herpes simplex virus type 1, as did four of ten mice that were treated with 50 excimer laser pulses. Ocular shedding of herpes simplex virus was detected in four of ten mice that were treated with ethylenediamine-tetraacetic acid (EDTA) scraping of the corneal epithelium without laser keratectomy, and in six of ten mice on which combined EDTA-facilitated epithelial removal was performed followed by the application of ten excimer laser pulses. In both EDTA-treated groups, viral shedding was prolonged and 18 of 20 mice developed marked corneal opacification or neovascularization, or both. Corneal photoablation with the excimer laser may induce reactivation of latent herpes simplex virus, even in mice with clear and smooth-appearing corneas, and should be considered in the differential diagnosis of humans with persistent corneal epithelial defects after refractive or therapeutic excimer procedures.

Intraoperative measurement of the elastic modulus of the vocal fold. Part 2. Preliminary results

This paper presents initial clinical experience using a device capable of measuring the transverse elastic modulus of the vocal fold. These initial results indicated that the device may be useful in determining stiffness inequalities between the vocal folds.

EAE cerebrospinal fluid augments in vitro phagocytosis and metabolism of CNS myelin by macrophages

Previous studies from this laboratory have shown that CNS myelin is phagocytized and metabolized by cultured rat macrophages to a much larger extent when myelin is pretreated with serum containing antibodies to myelin constituents than when it is left untreated or pretreated with non-specific serum. In this study the effect of cerebrospinal fluid (CSF) from rabbits with experimental allergic encephalomyelitis (EAE) in promoting myelin phagocytosis was examined. Fourteen rabbits were immunized with purified myelin in Freund's complete adjuvant, seven of which developed clinical EAE symptoms. Serum and CSF were collected from EAE and control rabbits, and the CSF was centrifuged to remove cells. Sera and CSF from these rabbits and from Freund's adjuvant-immunized controls and untreated controls were measured for IgG content by radial diffusion assay, their myelin antibody characteristics were analyzed by immunoblots, and the ability of these serum and CSF samples to promote myelin phagocytosis when used for myelin opsonization was examined. The ability of a CSF sample to enhance radioactive myelin uptake and phagocytosis by cultured macrophages as measured by the appearance of radioactive cholesterol ester was linearly proportional to its total IgG titer, and correlated approximately both with clinical symptoms of the animal and the presence of antibody against the myelin constituents myelin basic protein, proteolipid protein, and galactocerebroside. The cholesterol esterification activities of EAE sera correlated to a lesser extent with IgG levels and clinical symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Laryngeal paralyses: theoretical considerations and effects on laryngeal vibration

The neurological causes of vocal fold paralyses have been well documented. However, the effect of these disorders on laryngeal vibration is not well understood. A theoretical four-mass model of the larynx, based on the work of Ishizaka and Isshiki (1976) and Koizumi, Taniguchi, and Hiromitsu (1987), was developed and adapted to simulate laryngeal biomechanical behavior. The model was used to evaluate various states of asymmetric laryngeal vibration. Input parameters that relate observed laryngeal function and model simulation were developed. Laryngeal paralyses were simulated by their predicted effect on these parameters. Simulations were compared with available data on glottal vibration in laryngeal paralyses. Complex modes of vibration were seen with certain combinations of asymmetrical lower mass stiffness and initial glottal gap.

Otolaryngologic manifestations of the mucopolysaccharidoses

A retrospective review of 45 children with mucopolysaccharidoses was performed to determine the frequency of complications related to the head and neck. In this series, every patient had at least one complication involving the head and neck region, and in over half, operative intervention by the otolaryngologist was required. Upper airway obstruction occurred in 17 (38%) and necessitated a tracheostomy in 7 (16%). Cervical spine instability occurred in 8 (18%), making airway management difficult. Recurrent respiratory infections occurred in 17 (38%), and chronic recurrent middle ear effusions were noted in 33 (73%). This review demonstrates that children afflicted with the mucopolysaccharidoses frequently have otolaryngologic-related complications that are common throughout their life span and often the primary management issue in their continuing care. The otolaryngologic management of these patients is outlined based on the results of this study and review of the relevant literature.

Beta-endorphin and corticotropin immunoreactivity and specific binding in the neuromuscular system of obese-diabetic mice

Immunoreactivity for two derivatives of pro-opiomelanocortin, beta-endorphin and alpha-melanocortin (or corticotropin), was demonstrated, using a conventional immunoperoxidase method, in some of the intramuscular nerves in muscle sections from obese diabetic (ob/ob) mice and homozygous lean (+/+) mice. The endplate regions were visualized in the sections by staining for acetylcholinesterase reaction product. The proportion of muscle endplates with beta-endorphin-immunoreactive motor nerves was approximately 2.5-fold higher in soleus and extensor digitorum longus muscles and approximately 1.5-fold higher in the diaphragm of the obese (ob/ob) mice compared to the normal lean mice. The proportion of muscle endplates with alpha-melanotropin-immunoreactive motor nerves was between 30 and 53% lower, depending on the muscle type, in the ob/ob mice compared to the lean mice. The muscles of ob/ob and lean mice were investigated for the presence of specific binding sites for [125I]beta-endorphin and for [125I]corticotropin, using autoradiography. Some muscle fibres in soleus, extensor digitorum longus and diaphragm in both the ob/ob and the lean mice exhibited specific binding sites for the radioactive ligands. The binding sites were distributed over the entire surface in these muscle fibres. In the ob/ob mice the number of muscle fibres with specific [125I]beta-endorphin binding sites was six-fold higher in soleus and approximately 10-fold higher in extensor digitorum longus and diaphragm, than in the corresponding muscles of the lean mice. In contrast, the number of muscle fibres with specific [125I]corticotropin binding sites was similar in obese (ob/ob) and lean mice.(ABSTRACT TRUNCATED AT 250 WORDS)

A model for evaluating the cost-effectiveness of cholesterol-lowering treatment

We describe and illustrate the use of a generalizable model for evaluating the cost-effectiveness of alternative cholesterol-lowering treatments. We combine standard incidence-based techniques for measuring the cost of illness with logistic risk functions from the Framingham Heart Study to project, for persons with known coronary risk characteristics, the likelihood of developing coronary heart disease (CHD) over a lifetime as well as a number of related outcomes, including the expected loss of years of life due to CHD, the expected lifetime direct and indirect costs of CHD, and the changes in these outcomes that would result from cholesterol-lowering treatment.