A humoral response to OSP in multiple sclerosis: A molecular mimic?

Oligodendrocyte-specifie protein (OSP) is a recently isolated novel protein found only in CNS laminar myelin and therefor is a good candidate as an autoantigen in patients with MS. In order to determine the humoral response in patients with MS. Westren blot analysis was performed on CSF from 6 patients with clinically stable relapsing MS (rMS) and 2 normal controls. All 6 of the CSF samples from rMS patients contained anti-OSP antibodies and none were detected in controls. Peptide mapping determined that the antigenic response was directed at a 7 amino acid peptide (OSP 114-120) which was 71% homologous with several common viral and bacterial proteins and 100% identical to the human OSP protein. ELISAs were performed using OSP 114-20 as antigen on a total 32 MS patints followed at UCLA, 53 MS patients from the National Neurological Rescarch Specimen Bank (NNRSB), and on 51 neurological control samples. Eighty % of UCLA rMS patients had an OSP ELISA reading above 0.55 OD units (median ± SD, 0.94 ± .35) while 0 of 14 CSF samples from HTLV-1 patients and normal controls had values above 0.55 units (0.28 ± .12; p<.01). Similar results were found in specimens from the NNRSB. No differences in anti-OSP titers were found in serum of MS and control patients. ELISAs performed on CSF samples using homologus viral peptieds as antigen (e.g. EBV, HSV HIV) showed a close correlation with anti-OSP 114-120 titers, and in some, the anti-viral titers far exceeded them. These data demonstrate a specific humoral response directed against a region of OSP in rMS patinets which cross reacts with several common viral peptides and suggests a possible role of molecular mimicry in the development of MS.

Disrupted compaction of CNS myelin in an OSP/Claudin-11 and PLP/DM20 double knockout mouse

OSP/claudin-11 and PLP are both tetraspan proteins concentrated in CNS myelin. It has been proposed that they have a structural role in myelin formation and maintenance due to their localization and concentration in membrane sheaths. This hypothesis is not supported by the fact that both OSP/claudin-11- and PLP-null mice have relatively normal-appearing myelin and mild neurological deficits. Since both OSP/claudin-11 and PLP are abundant in myelin and have similar structures, the mild phenotypes of the knockout mice are likely due to compensatory mechanisms. Here we show that when both OSP/claudin-11 and PLP genes are knocked out, mice had severe neurological deficits, markedly abnormal myelin compaction, and smaller axon diameters. Interestingly, when either of these genes was knocked out, the expression of the other protein was increased. These data demonstrate that OSP/claudin-11 and PLP have essential structural functions in maintaining normal compact myelin and there is redundancy in their functions.

Deep Brain Stimulation in Intraoperative MRI Environment - Comparison of Imaging Techniques and Electrode Fixation Methods

We performed 118 consecutive DBS cases from November 1999 to June 2002. Intraoperatively there were 10 cases studied with fluoroscopy, 73 with 0.2 Tesla (T) MRI and 35 with 1.5 T MRI. Ten electrodes were secured by Medtronic caps, 25 by methyl methacrylate with titanium miniplates, and 82 by Navigus caps. The 3-dimensional displacement between the planned target and actual electrode position (3DD) was determined by fusing the postoperative MRI with the preoperative imaging. The 3DD for using Medtronic caps, methyl methacrylate with miniplates, and Navigus caps were 4.80 +/- 3.16, 2.64 +/- 1.26 and 2.23 +/- 1.15 mm (mean +/- SD), respectively. Navigus caps had statistically significant accuracy (P = 0.03) in holding the electrode when compared with Medtronic caps, and it facilitated electrode revision. The fixation devices significantly affect the final vertical position of the electrode. The 3DD for fluoroscopy, 0.2 T and 1.5 T MRI cases were 4.80 +/- 3.16, 2.31 +/- 1.21 and 2.34 +/- 1.14 mm (mean +/- SD), respectively. No statistically significant difference (P = 0.91) in 3DD was demonstrated between 0.2 T and 1.5 T MRI cases. The presence of intraoperative 1.5 T MRI allowed near real-time electrode position confirmation and early detection of hemorrhagic complications. Satisfactory microelectrode recording was feasible in low-field 0.2 T and high-field 1.5 T MRI environments. Further studies on performing DBS in real-time intraoperative MRI are warranted.

Cerebrospinal fluid immunoglobulin G promotes oligodendrocyte progenitor cell migration

Multiple sclerosis (MS) is characterized by demyelination of the CNS with associated neurological deficits. Remyelination can occur but is often incomplete. The process of myelin repair requires the proliferation and migration of oligodendrocyte progenitor cells (OPC) into the lesion from the neighboring areas. OPC migration is altered by several factors, including antibodies that bind to OPC surface proteins. We have previously reported elevated anti-OSP/claudin-11 antibodies in the cerebrospinal fluid (CSF) of MS patients and that anti-OSP/claudin-11 antibodies generated in rabbits can inhibit OPC migration. In the study presented here, we investigated the effect of CSF IgG from MS patients and controls on OPC migration in culture. Rat OPC cultured with CSF from MS patients tended to migrate more than those cultured with control CSF, but this did not reach statistical significance. To determine whether the IgG fraction in the CSF influenced migration, we removed it using protein-A sepharose. A dramatic decrease in OPC migration was found in both MS (45 +/- 24 vs.16 +/- 9) and control (40 +/- 19 vs. 22 +/- 13) samples after IgG was removed (P <.05). Anti-OSP/claudin-11 antibody concentration did not significantly correlate with OPC migration. These data demonstrate that CSF IgG promotes OPC migration. Identification of the specific IgG fraction responsible for this effect could lead to novel therapies to promote recovery in MS.

Payment levels, resource use, and insurance risk of medicaid versus private insured in three states

Concerns with access and costs in the Medicaid program often lead policy makers to consider alternatives. These include subsidizing poor persons' purchases of health insurance in private markets or integrating Medicaid beneficiaries into commercial managed care systems. As policy makers consider such alternatives, a persistent question is, apart from the disabled within Medicaid, do younger Medicaid enrollees represent a different insurance risk than people of similar age and sex within private insurance pools? We use 1994 data from Georgia, Mississippi, and California to assess relative payment levels, resource use/costs, and risk-adjusted utilization of fee-for-service (FFS) Medicaid enrollees versus privately insured people. When resources are valued at private prices, the use by Medicaid enrollees represents a higher cost. After risk adjustment, Medicaid enrollee resource use appears higher than expected for the privately insured only for outpatient facility visits in the southern states and for inpatient days by pregnant women in California Medi-Cal. Indeed, we find evidence that Medicaid enrollees are underserved relative to their health needs. Given the higher dollar value of their resource usage, apparently obtained under FFS at discounted provider rates, and the lack of evidence on significant overuse relative to need, their integration into private provider systems appears challenging.

T-cell responses to oligodendrocyte-specific protein in multiple sclerosis

Oligodendrocyte-specific protein (OSP) is concentrated in CNS myelin and is a potential autoantigen in the development of multiple sclerosis (MS). We performed proliferation assays with lymphocytes from MS patients and normal controls. OSP peptide-induced proliferation was common in relapsing-remitting MS and controls samples but was less pronounced in samples from secondary progressive MS subjects. These data demonstrate that OSP-reactive T cells are part of the normal immune repertoire and therefore have the potential to contribute to the pathogenesis of MS. Given the lack of specificity to MS, OSP-reactive T-cells are unlikely to be solely responsible for the disease process.

How rural physicians compare on cost and quality measures for Medicaid ambulatory care episodes

This study compares the costs and quality of episodes of care for two common childhood illnesses, urinary tract infections (UTI) and otitis media (OM), across providers practicing in rural, small town, and urban counties in Alabama in 1992. The data source is Medicaid claims data for children under age 8 who were treated for these conditions. The study found that episodes cared for by rural providers were less expensive than episodes cared for in other locations, both because fewer rural episodes included outpatient facility charges and because fewer ancillary services were provided in rural settings. Researchers also found that, even controlling for physician characteristics and patient demographic and utilization factors, rural episodes were significantly less likely to include two process measures of quality of care: fewer rural UTI episodes included urine cultures, and fewer rural OM episodes included follow-up visits. This study suggest that, as a group, rural physicians may have a favorable cost profile but a potentially unfavorable care content profile, compared with other physicians. Both practice profile data and explicit care recommendations need to be available to physicians so thy can monitor, defend, or alter their clinical practices.

Staged bilateral pallidotomy for treatment of Parkinson disease

OBJECT

Several investigators have described the motor benefits derived from performing unilateral stereotactic pallidotomy for the treatment of Parkinson disease (PD), but little is known about the efficacy and complication rates of bilateral procedures. The goal of this study was to assess both these factors in 12 patients.

METHODS

Eleven patients with medically intractable PD underwent staged bilateral pallidotomy and one patient underwent a simultaneous bilateral procedure. Unilateral pallidotomy resulted in an improvement in the patients' Unified Parkinson Disease Rating Scale (UPDRS) total scores and motor subscores, Hoehn and Yahr stages, and Schwab and England Activities of Daily Living scores. There were no complications. The second procedures were performed 5 to 25 months after the first, and nearly complete 3-month follow-up data are available for eight of these patients. Staged bilateral pallidotomy did result in further improvements in some symptoms, but the patients proved to be less responsive to levodopa. In contrast to outcomes of the initial unilateral pallidotomy, there were significant complications. One patient suffered an acute stroke, two patients suffered delayed infarctions of the internal capsule, four patients had mild-to-moderate worsening of speech and increased drooling, and one patient complained of worsening memory.

CONCLUSIONS

Bilateral pallidotomy results in modest benefits but is associated with an increased risk of complications.

Treatment of a patient by vaccination with autologous dendritic cells pulsed with allogeneic major histocompatibility complex class I-matched tumor peptides. Case Report

Dendritic cells (DCs) are antigen-presenting cells that play a central role in the initiation and modulation of antitumor immune responses. In this pilot study, we investigated the ability of autologous DCs pulsed ex vivo with allogeneic major histocompatibility complex class I-matched glioblastoma peptides to stimulate host antitumor immune responses when injected as a vaccine. A patient with recurrent brainstem glioblastoma multiforme (GBM) received a series of three intradermal immunizations of antigen-pulsed DCs on an outpatient basis following surgical debulking of her posterior fossa tumor. Dendritic cell vaccination was well tolerated, and no clinical signs of autoimmunity or experimental allergic encephalomyelitis were detected. She developed a measurable cellular immune response against the allogeneic glioblastoma peptides used in her vaccine preparation, as demonstrated by in vitro T-cell proliferation assays. In addition, increased T-cell infiltration was noted within the intracranial tumor site in the biopsy sample obtained following DC vaccination. An objective clinical response, however, was not evident, and this patient eventually died 21 months after her disease was diagnosed. To our knowledge, this is the first patient with brain cancer ever to be treated with DC-based immunotherapy. This case illustrates that vaccination with DCs pulsed with acid-eluted glioblastoma peptides is feasible and can induce systemic antigen-specific immunity in a patient with recurrent GBM. Additional studies are necessary to determine the optimum DC doses and antigen loading conditions that may translate into clinical effectiveness and survival benefit for patients with brain tumors. Phase I trials for malignant glioma are currently underway.

The use of Medicaid claims as a supplementary source of information on quality of asthma care

This study examines the correspondence between medical records and Medicaid claims to determine whether claims are a valid source of data for monitoring quality of asthma care. A total of 460 claims for care encounters were matched to medical records of the encounters. While most of the diagnoses and procedures recorded on the claims were documented in medical records, claims failed to identify 29% of encounters with asthma diagnoses and 45% of nebulization procedures administered during encounters. About 30% of documented asthma prescriptions were not associated with filed claims, and about 30% of filed claims for asthma medication were not documented in medical records.

Function of tetraspan proteins in the myelin sheath

During the past few years, significant advances have been made in elucidating the mechanisms by which point mutations and altered gene dosages in tetraspan genes cause neurological disease. In addition, several new myelin tetraspans have been identified that are involved in adhesion, molecular trafficking, growth regulation, and migration of oligodendrocytes and Schwann cells.

Developmental expression of OSP/claudin-11

Oligodendrocyte-specific protein (OSP/claudin-11) is a major component of CNS myelin and has been recently added to the claudin family of tight junction proteins. In this study, the developmental expression of OSP/claudin-11 was determined using in situ hybridization, immunohistochemistry (IH), and Western blot analysis. OSP/claudin-11 mRNA was expressed in a bimodal fashion. During prenatal development, OSP/claudin-11 mRNA was abundant in developing meninges, in areas adjacent to cartilage, and in mesoderm. In postnatal animals, OSP/claudin-11 was expressed primarily in developing oligodendrocytes and to a lesser extent, in testes. Double-labeled IH using O2-A progenitor cells revealed that OSP/claudin-11 expression occurs from the early progenitor stage and continues in mature oligodendrocytes. Electron microscopic IH localized OSP/claudin-11 to laminar myelin in the adult CNS. Western blot analysis of OSP/claudin-11 in developing brain revealed the expression of two separate transcripts that were developmentally regulated. These data demonstrate that OSP/claudin-11 expression is highly regulated during development and, therefore, may play an important role in growth and differentiation of oligodendrocytes and other cells outside the CNS.

Involvement of OSP/claudin-11 in oligodendrocyte membrane interactions: role in biology and disease

Oligodendrocyte-specific protein (OSP/claudin-11) is a four transmembrane protein concentrated in central nervous system myelin. Recent evidence has emerged suggesting that OSP/claudin-11 is involved in membrane interactions at tight junctions and with the extracellular matrix. OSP/claudin-11 seems to modulate proliferation and migration of oligodendrocytes presumably through these interactions. Furthermore, evidence is presented implicating OSP/claudin-11 as an autoantigen in the development of autoimmune demyelinating disease.

Identification of a human glioma-associated growth factor gene, granulin, using differential immuno-absorption

Identification of the genes that are differentially expressed in brain tumor cells but not in normal brain cells is important for understanding the molecular basis of these neurological cancers and for defining possible targets for therapeutic intervention. In an effort to discover potentially antigenic proteins that may be involved in the malignant transformation and progression of human glioblastomas, a novel antibody-based approach was developed to identify and isolate gene products that are expressed in brain tumors versus normal brain tissue. Using this method, whereby tumor-specific antibodies were isolated and used to screen a glioblastoma cDNA expression library, 28 gene products were identified. Nine of these clones had homology to known gene products, and 19 were novel. The expression of these genes in multiple different human gliomas was then evaluated by cDNA microarray hybridization. One of the isolated clones had consistently higher levels of expression (3-30-fold) in brain tumors compared with normal brain. Northern blot analysis and in situ hybridization confirmed this differential overexpression. cDNA sequence analysis revealed that this gene was identical to a relatively new class of growth regulators known as granulins, which have tertiary structures resembling the epidermal growth factor-like proteins. The 2.1-kb granulin mRNA was expressed predominantly in glial tumors, with lower levels in spleen, kidney, and testes, whereas expression was not detected in non-tumor brain tissues. Functional assays using [3H]thymidine incorporation indicated that granulin may be a glial mitogen, as addition of synthetic granulin peptide to primary rat astrocytes and three different early-passage human glioblastoma cultures increased cell proliferation in vitro, whereas increasing concentrations of granulin antibody inhibited cell growth in a dose-dependent manner. The differential expression pattern, tissue distribution, and implication of this glioma-associated molecule in growth regulation suggest a potentially important role for granulin in the pathogenesis and/or malignant progression of primary brain neoplasms.

CNS myelin and sertoli cell tight junction strands are absent in Osp/claudin-11 null mice

Oligodendrocyte-specific protein (OSP)/claudin-11 is a recently identified transmembrane protein found in CNS myelin and testis with unknown function. Herein we demonstrate that Osp null mice exhibit both neurological and reproductive deficits: CNS nerve conduction is slowed, hindlimb weakness is conspicuous, and males are sterile. Freeze fracture reveals that tight junction intramembranous strands are absent in CNS myelin and between Sertoli cells of mutant mice. Our results demonstrate that OSP is the mediator of parallel-array tight junction strands and distinguishes this protein from other intrinsic membrane proteins in tight junctions. These novel results provide direct evidence of the pivotal role of the claudin family in generating the paracellular physical barrier of tight junctions necessary for spermatogenesis and normal CNS function.

Stereotactic pallidotomy in the treatment of Parkinson disease: an expert opinion

The objective of this workshop was to provide recommendations on several issues involving pallidotomy for patients with medically intractable Parkinson disease to physicians, patients, and other health care providers. An international consortium of experts in neurology, neurosurgery, and neurophysiology who had extensive experience with pallidotomy were invited to the workshop. Participants were sent background materials from the scientific literature for review-based participant recommendations. A proposed agenda was circulated to all participants before the workshop, and the final agenda was based on their recommendations. Topics were introduced at the workshop by members of the organizing committee, followed by extensive group discussion. A draft of a consensus statement, based on the previous day's discussion, was circulated and further modifications were made. The final statement was agreed on by all members. The conclusions of the participants were: (1) Pallidotomy should be performed only at centers that have a team of physicians with substantial expertise and experience in the field. (2) Patients with disabling idiopathic Parkinson disease, without dementia, and who have exhausted medical therapy should be considered for pallidotomy. (3) All patients should be examined by means of standardized rating scales both preoperatively and postoperatively to ensure quality of care at each center. (4) Symptoms that respond best to pallidotomy include medication-induced dyskinesias, rigidity, and tremor, while balance, gait disorders, and hypophonia are generally less responsive to surgery. Benefits of pallidotomy appear to be long lasting. (5) Each institution's complication rate should be discussed before surgery.

A humoral response to oligodendrocyte-specific protein in MS: a potential molecular mimic

OBJECTIVE

To determine the antibody response to oligodendrocyte-specific protein (OSP) in patients with MS.

BACKGROUND

OSP is a recently identified CNS-specific myelin protein that is abundant and therefore a candidate autoantigen in MS.

METHODS

The presence of anti-OSP antibodies was determined using Western blot analysis, peptide blots, and ELISA in patients with MS and in other neurologic and normal control subjects.

RESULTS

Using Western blot analysis, seven patients with relapsing-remitting MS (RRMS) were found to contain anti-OSP antibodies in their CSF that were not present in control subjects. Peptide mapping determined that the antibody response was directed to a seven aa peptide (OSP 114-120), which has 71% homology with several common pathogenic proteins. Using OSP 114-120 as antigen, ELISAs were performed on CSF from 85 MS and 51 control patients. Eighty percent of the samples from RRMS patients followed at the University of California at Los Angeles had an ELISA reading above 0.55 optical density units, whereas all 20 control CSF samples had values less than 0.55 U. Similar results were found in specimens from an outside research bank. ELISAs performed on CSF using homologous viral peptides as antigen showed a close correlation with anti-OSP 114-120 ELISA readings, and in some, the readings were higher than those using OSP peptides.

CONCLUSIONS

There is a specific humoral response directed against a region of OSP in RRMS patients that cross-reacts with several common viral peptides. This suggests a possible role for molecular mimicry in the development of MS.

Oligodendrocyte-specific protein peptides induce experimental autoimmune encephalomyelitis in SJL/J mice

Oligodendrocyte-specific protein (OSP) is a recently isolated and cloned, 207-aa, hydrophobic, four-transmembrane protein found in CNS myelin. It represents approximately 7% of total myelin protein. The OSP cDNA sequence has no significant homology with previously reported genes, but the predicted protein structure suggests that OSP is a CNS homologue of peripheral myelin protein-22. We previously reported the presence of anti-OSP Abs in the cerebrospinal fluid of relapsing-remitting multiple sclerosis (MS) patients, but not control patient groups. In this study, we tested the ability of a panel of 20-mer peptides with 10-aa overlaps, representing the sequence of murine OSP, to induce experimental autoimmune encephalomyelitis (EAE), an animal model for MS. SJL mice challenged with murine OSP peptides 52-71, 82-101, 102-121, 142-161, 182-201, and 192-207 exhibited clinical EAE. OSP:52-71 elicited severe relapsing-remitting EAE in some individuals. All other encephalitogenic peptides elicited, at most, a loss of tail tonicity from which the mice most often completely recovered. Mononuclear cell infiltrates and focal demyelination characteristic of EAE were evident. T cell proliferative responses were seen with all encephalitogenic peptides except 142-161 and 182-201. OSP peptides 72-91 and 132-151 did not cause clinical EAE, but did elicit robust proliferative responses. B10.PL and PL/J mice challenged with the same OSP peptide doses as SJL mice did not exhibit clinical EAE. These results in the SJL EAE model, together with the results from MS patient clinical samples, make OSP a promising candidate for autoantigenic involvement in MS.

Treatment of intracranial gliomas with bone marrow-derived dendritic cells pulsed with tumor antigens

OBJECT

An approach toward the treatment of intracranial gliomas was developed in a rat experimental model. The authors investigated the ability of "professional" antigen-presenting cells (dendritic cells) to enhance host antitumor immune responses when injected as a vaccine into tumor-bearing animals.

METHODS

Dendritic cells, the most potent antigen-presenting cells in the body, were isolated from rat bone marrow precursors stimulated in vitro with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4. Cultured cell populations were confirmed to be functional antigen-presenting cells on the basis of expressed major histocompatibility molecules, as analyzed by fluorescence-activated cell sorter cytofluorography. These dendritic cells were then pulsed (cocultured) ex vivo with acid-eluted tumor antigens from 9L glioma cells. Thirty-eight adult female Fischer 344 rats harboring 7-day-old intracranial 9L tumors were treated with three weekly subcutaneous injections of either control media (10 animals), unpulsed dendritic cells (six animals), dendritic cells pulsed with peptides extracted from normal rat astrocytes (10 animals), or 9L tumor antigen-pulsed dendritic cells (12 animals). The animals were followed for survival. At necropsy, the rat brains were removed and examined histologically, and spleens were harvested for cell-mediated cytotoxicity assays. The results indicate that tumor peptide-pulsed dendritic cell therapy led to prolonged survival in rats with established intracranial 9L tumors implanted 7 days prior to the initiation of vaccine therapy in vivo. Immunohistochemical analyses were used to document a significantly increased perilesional and intratumoral infiltration of CD8+ and CD4+ T cells in the groups treated with tumor antigen-pulsed dendritic cells compared with the control groups. In addition, the results of in vitro cytotoxicity assays suggest that vaccination with these peptide-pulsed dendritic cells can induce specific cytotoxic T lymphocytes against 9L tumor cells.

CONCLUSIONS

Based on these results, dendritic antigen-presenting cells pulsed with acid-eluted peptides derived from autologous tumors represent a promising approach to the immunotherapy of established intracranial gliomas. which may serve as a basis for designing clinical trials in patients with brain tumors.

Entrance and exit of obstetrics providers in rural Alabama

In Alabama between 1985 and 1989, a total of 94 physicians outside of the four largest cities in the state dropped the obstetrics portion of their practices or left practice in their communities altogether. During the same period 82 physicians entered obstetrics practice in this area. The study presented here used survey and archival data to compare practice characteristics of generalists and specialists in rural and town counties who made different decisions about providing obstetrics care. More generalists left and more specialists entered practice both in town and in rural counties. Rural counties lost more obstetrics providers because more generalists provided the obstetrics care in these areas. Across both specialty and county categories, physicians in group practice who accepted Medicaid and had local access to larger numbers of patients were more likely to remain or begin new obstetric practices. During this period, some obstetrics specialists moved into rural communities that had previously supported only generalist physicians. These findings suggest that the options for organizing successful obstetrics practices have narrowed, putting solo and generalist physicians who operate small-scale obstetrics practices at a disadvantage. These physicians also face competition from obstetrics specialists who are beginning to enter practice in the rural areas of the state. Designing policies that effectively improve geographic access to care requires a realistic understanding of the practice constraints faced by obstetrics providers. For example, as centralized specialist group practices serve residents from surrounding rural areas, programs that facilitate linkages, such as satellite clinics and use of mid-level practitioners, can be promoted.(ABSTRACT TRUNCATED AT 250 WORDS)

Motor, cognitive, and behavioral performance following unilateral ventroposterior pallidotomy for Parkinson disease

OBJECTIVE

To evaluate the effects of ventroposterior pallidotomy on motor disability and on behavior and cognition in patients with medically intractable idiopathic Parkinson disease.

DESIGN

Detailed motor testing both while receiving and discontinuing levodopa medication, posturography, and neurocognitive and behavioral assessments were performed before and 3 to 6 months after unilateral ventroposterior pallidotomy.

SETTING

University-based movement disorder program.

PATIENTS

Thirty-two patients without dementia with medically refractory idiopathic Parkinson disease were studied.

MAIN OUTCOME MEASURES

Motor function and disability were measured using the Unified Parkinson's Disease Rating Scale, Hoehn and Yahr stage, and the Schwab and England Activities of Daily Living Scale. Dynamic balance was measured by sway (amplitude and velocity) using the Chattecx Balance System. Detailed cognitive and behavioral assessments were also performed both before and after surgery.

RESULTS

Eighty-three percent of patients experienced improvement of their total Unified Parkinson's Disease Rating Scale score at 3 to 6 months after surgery. Significant improvements were also seen in the contralateral Unified Parkinson's Disease Rating Scale motor subscore (78%) as well as in the contralateral Unified Parkinson's Disease Rating Scale total score both during the on and off period (78% and 79%, respectively). The Hoehn and Yahr stage, Schwab and England Activities of Daily Living Scale score, and dynamic balance when standing on foam also improved following unilateral pallidotomy in many patients. Cognitive performance remained relatively unchanged following surgery with the exception of category fluency, which exhibited a modest decline (P < .04). A significant improvement in depression was found on the Beck Depression Inventory.

CONCLUSIONS

Ventroposterior pallidotomy significantly improves motor performance and daily level of function in Parkinson disease. Cognition and behavior are not adversely affected in patients without dementia, and a cognitive screening battery is proposed.

Practice variation in the use of interventions in high-risk obstetrics

OBJECTIVE

To assess the relationship between clinical, demographic, and site-of-care factors and the use of tocolysis and corticosteroid therapy in the treatment of premature labor.

DATA SOURCE

Secondary clinical and demographic data collected for the five-center March of Dimes Prematurity Prevention clinical trial, 1983-1986.

STUDY DESIGN

We used logistic regression analysis in assessing the clinical, patient, and care site factors associated with the use of tocolysis and corticosteroid therapy during episodes of premature labor occurring to women enrolled in the trial. The two interventions were not subject to control in the trial, but were provided according to customary practice at the care site.

DATA EXTRACTION

A total of 4,625 episodes of labor occurring before 37 weeks gestation were identified from either preterm labor or preterm delivery records recorded for the 33,792 women enrolled in the trial.

PRINCIPAL FINDINGS

The use of tocolysis, an intervention that attempts to control premature labor contractions and that was widely used in high-risk obstetrics, varied almost exclusively by clinical factors. The use of corticosteroid therapy, a little used but effective intervention that reduces respiratory complications in premature infants, varied significantly by site of care and was used less frequently across sites and clinical conditions for minority group patients.

CONCLUSION

This study confirms the premise that practice variation on the basis of nonclinical factors occurs more commonly for interventions where there is more uncertainty about clinical indications and effectiveness. The study also identifies another area of clinical care in which the use of aggressive and relatively uncertain interventions is provided less frequently to minority group patients.

A conditionally immortalized glial cell line that expresses mature myelin proteins and functional GABA(A) receptors

We have isolated and characterized a conditionally immortalized glial cell line that expresses mature myelin proteins, as well as functional GABA(A) receptors. Glial cells were isolated from postnatal day 1 H-2Kb-tsA58 transgenic mice that contain the temperature-sensitive SV40 large T antigen oncogene under the control of an interferon-gamma-inducible promoter. A clonal line was isolated that grew rapidly under permissive conditions (33 degrees C in the presence of interferon-gamma), but not under nonpermissive conditions (37 degrees C in the absence of interferon-gamma). Cells expressed mRNAs of mature myelin proteins (myelin basic proteins and proteolipid protein) when grown under either permissive or nonpermissive conditions, but myelin basic proteins were detected only when cells were maintained at 37 degrees C. GABA induced an increase in intracellular calcium concentration, indicating the presence of functional receptors for this transmitter. Characterization of the GABA-evoked calcium response and whole-cell currents indicated that these responses were mediated by GABA(A) receptors. Reverse transcription-polymerase chain reaction revealed differential expression of mRNAs for specific GABA(A) receptor subunits. Messages for the alpha2, alpha4, beta1, and delta subunits were readily detected by reverse transcription-polymerase chain reaction, whereas messages for the alpha1, alpha3, alpha5, alpha6, beta2, beta3, and gamma1-3 subunits were not. As this cell line can be easily propagated and differentiated, it should provide a valuable tool in studying not only the development of oligodendroglia, but also the function of their transmitter receptors and myelin proteins.

Oligodendrocyte-specific protein (OSP) is a major component of CNS myelin

An oligodendrocyte-specific protein (OSP) cDNA was recently identified and found to be expressed primarily in oligodendrocytes and has a deduced amino acid sequence similar to that of peripheral myelin protein 22 (PMP-22). We raised antibodies against a synthetic peptide corresponding to OSP amino acid residues 179-194 which reacted with a 22 kd protein in mouse CNS. OSP immunoreactivity localized to spinal cord white matter tracts using immunohistochemistry in a similar distribution to that of MBP. OSP localized to CNS myelin biochemically with more than a 30-fold enrichment measured in purified myelin. We further purified the proteolipid fraction of myelin and determined that OSP contributes approximately 7% of total myelin protein making it the third most abundant protein in CNS myelin. No binding was found to several agglutinins or a HNK1-specific antibody suggesting that OSP is not a glycoprotein.

Impact of care setting on cost and quality under Medicaid

Medicaid claims data were used to compare the costs and care quality of ambulatory visits for two childhood illnesses, urinary tract infection (UTI) and suppurative otitis media (OM), in the fee-for-service Medicaid program in Alabama across three care settings: offices where patients had been seen before, offices where patients had not been seen before, and outpatient hospital departments. Forty percent of UTI visits and 46 percent of OM visits occurred in return office settings. Visits to outpatient hospital and first-time office settings were more expensive than those to return office settings, due to the billing of facility fees and the provision of additional services. Adherence to common measures of quality of care for both types of visits was low; 52 percent of UTI visits included urine cultures and 40 percent of OM visits included recheck visits. Adherence to these quality measures was significantly lower in visits occurring in hospital settings.

Prenatal ontogeny of the epidermal growth factor receptor and its ligand, transforming growth factor alpha, in the rat brain

Transforming growth factor alpha (TGF alpha) interacts with the epidermal growth factor receptor (EGF-R) to produce its biological effects. TGF alpha induces the proliferation and differentiation of central nervous system (CNS) astrocytes and pluripotent stem cells, as well as the survival and differentiation of postmitotic CNS neurons. Both TGF alpha and EGF-R have been localized to the postnatal CNS. As the majority of CNS neuronal proliferation and migration occurs antenatally, we have examined the ontogeny of TGF alpha and EGF-R in the embryonic rat brain by in situ hybridization. EGF-R mRNA was expressed in the brain as early as embryonic day 11 (E11; the earliest age examined). It was initially detected in the midbrain, with subsequent expression first in multiple germinal zones, followed by expression in numerous cells throughout the brain. In many brain areas, EGF-R mRNA appeared in germinal centers during the later stages of neurogenesis and the early stages of gliogenesis. In the midbrain, the distribution of EGF-R mRNA overlapped extensively with that of tyrosine hydroxylase mRNA, suggesting that fetal dopaminergic neurons express EGF-R. Immunocytochemistry was used to demonstrate the presence of EGF-R-immunoreactive protein in brain areas that expressed EGF-R mRNA on E15 and E20. The expression of TGF alpha in many brain structures preceded that of EGF-R mRNA. TGF alpha mRNA was distributed throughout many non-germinal centers of the brain on E12 and later. Some brain areas, such as the external granule cell layer of the cerebellum, expressed EGF-R, but not TGF alpha mRNA. Northern blot analysis demonstrated that mRNA species for both TGF alpha and EGF-R were similar in embryos and adults. These data indicate that TGF alpha and EGF-R are positioned to have a role in the genesis, differentiation, migration, or survival of numerous cell populations in the embryonic brain.

TRPM-2 expression and tunel staining in neurodegenerative diseases: studies in wobbler and rd mice

Neuronal apoptosis has been described during development but little is known about whether apoptosis plays a role in neurodegenerative disease. Neurodegenerative cell death can be difficult to study because it is often a slow process and it is limited to only a few cells among many nondying cells. We used molecular methods to study cell death in the spinal cords of wobbler mice, a model of motoneuron disease, and compared it to retinas of rd mice, a model of retinitis pigmentosa, where it is known that photoreceptors die by apoptosis. Increased levels of mRNA of testosterone-repressed prostate message 2 (TRPM-2) were found in motoneurons of wobbler mice and the retinas of rd mice. In motoneurons, TRPM-2 mRNA colocalized with increased expression of the message for growth-associated protein (GAP-43). In rd retinas, TRPM-2 mRNA was localized to ganglion cells of the inner retina known to survive the disease. These suggest that TRPM-2 expression is associated with cell membrane remodeling in surviving cells associated with synaptic reorganization or change in afferent input. In situ labeling of fragmented DNA (TUNEL staining) identified dying photoreceptors in the rd mouse. In the wobbler spinal cords dying motoneurons were not labeled. These data suggest that the process of neurodegenerative motoneuron cell death in wobbler mice is different from the apoptotic process of rd photoreceptors.

Exclusion of the beta-subunit of type II calmodulin kinase for the wobbler spinal muscular atrophy gene

The wobbler mouse (wr) is an attractive model for studying motor neuron disease but the genetic defect is unknown. The beta-subunit of calmodulin kinase II (beta-CaMK II) is a good candidate for the wr mutation because of its chromosomal localization and tissue distribution. In this report, we found normal levels of CaM KII mRNA and enzyme activity making it highly unlikely that a mutation in the beta-CaM KII gene is the cause of the wr phenotype.

The effects of patient volume and level of care at the hospital of birth on neonatal mortality

OBJECTIVE

To examine the effects of neonatal intensive care unit (NICU) patient volume and the level of NICU care available at the hospital of birth on neonatal mortality.

DESIGN

Birth certificate data linked to infant death certificates and to infant discharge abstracts were used in a logistic regression model to control for differences in each patient's clinical and demographic risks. Hospitals were classified by the level of NICU care available (no NICU: level I; intermediate NICU: level II; expanded intermediate NICU: level II+: tertiary NICU: level III) and by the average patient census in the NICU.

SETTING

All nonfederal hospitals in California with maternity services.

PATIENTS

All births in nonfederal hospitals in California in 1990 (N=594104), 473209 (singletons only) of which were successfully linked with discharge abstracts. Of these infants, 53229 were classified as likely NICU admissions.

MAIN OUTCOME MEASURES

Death within the first 28 days of life, or within the first year of life, if continuously hospitalized.

RESULTS

Patient volume and level of NICU care at the hospital of birth both had significant effects on mortality. Compared with hospitals without an NICU, infants born in a hospital with a level III NICU with an average NICU census of at least 15 patients per day had significantly lower risk-adjusted neonatal mortality (odds ratio, 0.62; 95% confidence interval, 0.47-0.82; P=.002). Risk-adjusted neonatal mortality for infants born in smaller level III NICUs, and in level II+ and level II NICUs, regardless of size, was not significantly different from hospitals without an NICU, and was significantly higher than hospitals with large level III NICUS.

CONCLUSIONS

Risk-adjusted neonatal mortality was significantly lower for births that occurred in hospitals with large (average census, >15 patients per day) level III NICUs. Despite the differences in outcomes, costs for the birth of infants born at hospitals with large level III NICUs were not more than those for infants born at other hospitals with NICUs. Concentration of high-risk deliveries in urban areas in a smaller number of hospitals that could provide level III NICU care has the potential to decrease neonatal mortality without increasing costs.

Isolation and characterization of a novel oligodendrocyte-specific protein

Myelin plays a critical role in nervous system function and alterations in myelin-specific proteins cause a variety of neurologic disorders. We isolated a novel cDNA from the CNS that shares little nucleotide sequence homology with previously reported genes but appears to encode a protein related to peripheral myelin protein-22 (PMP-22) based on its amino acid sequence, predicted structure, and cellular localization. PMP-22 is important in peripheral myelination and Schwann cell proliferation, and mutations in its gene cause diseases of peripheral nerves. The isolated cDNA is 1.8 kb in length with an open reading frame of 621 bp. Northern blot analysis detected hybridization of labeled cDNA with a single 2.1-kb transcript only in the CNS. In situ hybridization revealed expression of this cDNA in oligodendrocytes of brain and spinal cord as well as in oligodendrocyte-enriched cultures; therefore we have named it oligodendrocyte-specific protein (OSP) cDNA. An OSP-specific polyclonal antibody reacted with a single 22-kd protein present in CNS myelin and oligodendrocytes. Developmental expression of OSP mRNA in the spinal cord was similar to that of the mRNA for a major myelin protein, proteolipid protein (PLP), and similar to PMP-22 in peripheral nerves. Since OSP is localized to oligodendrocytes and myelin, has a similar structure with PMP-22, and has a developmental pattern of expression like other myelin proteins, it probably has an important role in CNS myelinogenesis.

Chromosomal localization of murine and human oligodendrocyte-specific protein genes

Oligodendrocyte-specific protein (OSP) is a recently described protein present only in myelin of the central nervous system. Several inherited disorders of myelin are caused by mutations in myelin genes but the etiology of many remain unknown. We mapped the location of the mouse OSP gene to the proximal region of chromosome 3 using two sets of multilocus crosses and to human chromosome 3 using somatic cell hybrids. Fine mapping with fluorescence in situ hybridization placed the OSP gene at human chromosome 3q26.2-q26.3. To date, there are no known inherited neurological disorders that localize to these regions.

Patient's choice of hospital or office for Medicaid ambulatory care in Alabama

The primary policy option that has been suggested to states over the years for shifting care for Medicaid beneficiaries away from hospital sites and toward office sites has been to raise Medicaid fees to physicians on the assumption that this increases the geographic availability of office-based care, which then naturally attracts Medicaid clients away from hospital sites. This study uses Medicaid claims data from the state of Alabama to assess the role of geographic provider availability relative to other factors in families' decisions to select a hospital or an office for an illness visit to a primary care or to a specialist physician. The authors examined the last ambulatory visit for an illness made by continuously enrolled children under age 8 in the first half of 1991. The authors found that both higher Medicaid office practice density and the presence of larger Medicaid office practices were associated with choice of an office for ambulatory care, whereas the presence of larger Medicaid hospital practices were associated with choice of a hospital for care. Controlling for provider availability, hospital users were less likely to have sought previous care for illness during the year, and were more likely to be rural residents, to have traveled away from their home counties for care, and to be eligible for Medicaid through Aid to Families with Dependent Children, rather than through the program's income expansions. We conclude that increased office-based provider availability must be coupled with improved access tor new, remote, and very low income families if Medicaid clients are to be expected to voluntarily shift their choice if site for ambulatory care.

Patterns of care received by Medicaid recipients with urinary tract infections

BACKGROUND

Urinary tract infections (UTIs) occur commonly in children and may lead to substantial morbidity. Most experts recommend urine cultures for diagnosing UTIs in children. In addition, most experts recommend imaging studies in a portion of children diagnosed with UTIs.

PURPOSE

The purpose of this study was to assess how rates of performance of urine cultures and imaging studies for children in the Alabama Medicaid program diagnosed with a UTI vary by patient demographics, provider characteristics, and service locations.

METHODS

The study design was a retrospective review of Alabama Medicaid claims data. Children were included as UTI cases if they had a Medicaid claim for urinary tract infections during 1991, were continuously enrolled in Medicaid for that year, and were younger than 8 years of age. Claims were grouped into episodes of care, and episodes were assigned to a diagnosing physician. Physician locations were classified as rural, suburban, or urban using demographic data. Specific laboratory and imaging procedures were identified using CPT codes (Physician's Current Procedural Technology Codes, 4th Edition).

RESULTS

We identified 404 episodes of UTI occurring in 380 children. Only 47% of episodes were associated with claims for urine cultures. Claims for urine cultures were more frequently filed by pediatricians in urban locations. In the subset of 114 patients with multiple UTI episodes, only 68% had imaging studies specific for the urinary tract. Only 44% received both a voiding cystourethrogram and renal ultrasound.

CONCLUSIONS

Claims data suggest that physicians underuse urine cultures in diagnosing UTIs in Alabama pediatric Medicaid recipients. Urban-based pediatricians perform better than other types of physicians. Imaging studies are also used less frequently than is commonly recommended.

Access to neonatal intensive care for low-birthweight infants: the role of maternal characteristics

OBJECTIVES

This study assessed the impact of mother's race, insurance status, and use of prenatal care on very low birthweight infant delivery in or transfer to hospitals with neonatal intensive care units (ICUs).

METHODS

Multivariate analysis of Alabama vital statistics records between 1988 and 1990 for infants weighing 500 to 1499 g was conducted, comparing hospital of birth and maternal and infant transfer status, and controlling for infant birthweight and for maternal pregnancy history and demographic characteristics.

RESULTS

With other factors adjusted for, non-White mothers with early prenatal care were more likely than White mothers to deliver their very low birthweight infants in hospitals with neonatal ICUs without transfer. Among the mothers who presented first at hospitals without such facilities, those who had late prenatal care were less likely than those with early care to be transferred to hospitals with neonatal ICUs before delivery. Medicaid coverage increased the likelihood of antenatal transfer for White women. Likelihood of infant transfer was not associated with these maternal characteristics.

CONCLUSIONS

Maternal race, prenatal care use, and insurance status may influence the likelihood that very low birthweight infants will have access to neonatal intensive care. Interventions to improve perinatal regionalization should address individual and system barriers to the timely referral of high-risk mothers.

Conceptual and methodologic problems in the evaluation of a new burn treatment modality

This article describes and analyzes major conceptual and methodologic problems that occurred during the implementation and evaluation of a new home-based burn treatment modality. Problems described include those of conceptualization, measurement, patient sampling, and follow-up, data collection, and analysis. The origins of each specific problem are discussed along with their effects on the implementation of the project and project outcomes. Solutions for each set of problems are suggested.

Regulation of type-II calmodulin kinase: functional implications

Calmodulin-kinase II (CaM kinase) is a calcium/calmodulin-dependent protein kinase which is highly enriched in the nervous system and mediates many of calcium's actions. Regulation of CaM kinase activity plays an important role in modulating synaptic transmission, synaptic plasticity and in neuropathology. Primary regulation of CaM kinase occurs via changes in intracellular calcium concentrations. Increased calcium stimulates protein kinase activity and induces autophosphorylation. Autophosphorylation of CaM kinase at specific sites results in altered activity and responsiveness to subsequent changes in calcium concentrations. Intracellular translocation of CaM kinase also appears to result from autophosphorylation. These mechanisms of regulation play an important role in synaptic plasticity (e.g., Aplysia ganglia), status epilepticus and cerebral ischemia. Long-lasting alterations in the expression of CaM kinase have been demonstrated in the kindling model of epilepsy and in monocular deprivation and therefore modulation of gene expression, in addition to autophosphorylation and translocation, appears to be another important mechanism of regulating CaM kinase activity.

Long-lasting decreases of type II calmodulin kinase expression in kindled rat brains

The kindling model of epilepsy is associated with long-lasting changes in type II calmodulin kinase (CaM kinase) activity and immunoreactivity. In order to determine the mechanism of these alterations, we measured gene expression of CaM kinase using in situ hybridization in septally kindled rat brains and paired controls using a 35S-labeled riboprobe for the beta subunit of the enzyme. We found CaM kinase mRNA concentrated in the hippocampus and other limbic structures. Kindling decreased hippocampal CaM kinase mRNA by 30% in CA1, 34% in CA2, 35% in CA3 41% in CA4, and 29% in the dentate gyrus. Hybridization was also decreased by 21% in the cerebral cortex but not in the lateral septum. These changes are similar in distribution and direction to those previously measured by immunohistochemistry. These data suggest that altered CaM kinase activity and immunoreactivity associated with kindling reflect long-lasting alterations in gene expression of this important synaptic protein, and provide further evidence for its possible importance in the kindling phenomenon.

Medical malpractice and access to obstetrical care in Alabama

The medical malpractice insurance crisis of the mid-1980s has abated, but nonetheless there are concerns that the threat of liability continues to have a deleterious effect on access to obstetrical services for low income women. Currently, at the national level there is discussion over whether the tort system should be replaced with a no fault compensation scheme similar to the worker's compensation system. Florida and Virginia have already enacted no fault compensation schemes for certain birthrelated neurological injuries. After reviewing the situation in Alabama with respect to claim frequency and severity, insurance costs and access to obstetrical care, we will examine proposals for a fundamental restructuring of the medical liability system.

Determinants of rural travel distance for obstetrics care

This study examines the distances traveled for inpatient obstetrics care by women residing in rural Alabama in 1983 and 1988. During that time 23 rural hospitals in the state stopped providing obstetrics services and mean travel distances increased by 6.8 miles. However, in 1988 50% of rural pregnant women bypassed the nearest rural hospital still providing obstetrics services. Multivariate techniques are used to examine the effects of distance and service offerings of rural hospitals and their substitutes on the actual distance traveled for care. Patient characteristics are also considered. The most important finding is that a 5% increase in per capita income in the woman's home county is associated with a 20% increase in actual travel distance, other things equal. Implications for rural health policy are discussed.

Kindling induced changes in calmodulin kinase II immunoreactivity

The distribution of type II calmodulin kinase (CaM kinase) immunoreactivity was studied in control and septally kindled rat brains. CaM kinase was concentrated in limbic structures, such as the hippocampus, lateral septum and amygdala. Within the hippocampus, the molecular layer of the endal limb of the dentate gyrus, the stratum radiatum, and lacunosum moleculare of CA1 were the most heavily stained regions. The cerebellum was stained only in the molecular and Purkinje cell layers, and very low amounts of immunoreactive protein were present in the brainstem and white matter. Kindling resulted in a significant decrease in CaM kinase immunoreactivity in CA3 and in the dentate of the ventral hippocampus but not in the lateral septum. These data suggest that kindling decreases the number of CaM kinase molecules or alters its antigenic distribution, and provides further evidence that alterations of this enzyme may be important in the kindling phenomenon.

Localization of retinal calmodulin kinase

The localization of calmodulin kinase II (CaM kinase) was studied in the retina by light and electron microscopic immunocytochemistry, and by enzymatic and immunoblot assay of cellular and subcellular tissue fractions. By light microscopy, both mono- and polyclonal antibodies revealed CaM kinase-like immunoreactivity in the inner and outer plexiform regions (synaptic layers), retinal pigment epithelium (RPE), and ganglion cells. The inner nuclear layer and photoreceptor outer segments stained much less intensely, and the outer nuclear layer did not stain. Electron microscopy confirmed the high concentration of immunoreactive protein in RPE and minimal outer segment staining. In addition, photoreceptor inner segments also contained CaM kinase-like immunoreactivity. Calcium and calmodulin stimulated phosphate incorporation into proteins of retinal cytosol and of isolated and cultured RPE. Calcium- and calmodulin-dependent kinase activity was present to a lesser degree in crude nuclei and synaptic membranes and was absent in isolated rod outer segments. Immunoblot analyses were consistent with enzymatic assays and immunocytochemistry. These data suggest that retinal CaM kinase is ideally located to play an important role in synaptic transmission and modulation of visual processes. Furthermore, its presence in RPE implies that CaM kinase may have a more ubiquitous role in regulating cellular processes than was previously recognized.

A retinal calmodulin-dependent kinase: calcium/calmodulin-stimulated and -inhibited states

A calcium/calmodulin-dependent protein kinase was isolated from retina. The retinal enzyme is composed exclusively of 50-kilodalton (kD) subunits and has a molecular mass of approximately 275 kD, in contrast to forebrain calmodulin kinase II, which is composed of 50-kD and 60-kD subunits in a 3:1 ratio and has a molecular mass of approximately 520 kD. Similar substrate specificities, kinetic properties, capacity to bind calmodulin, and immunoreactivity suggest that the retinal kinase is an isoenzyme of forebrain calmodulin kinase II. Both kinases autophosphorylate in an intramolecular manner; however, autophosphorylation has different effects on the activities of the two enzymes. Autophosphorylation of retinal calmodulin kinase converts the enzyme from a calcium/calmodulin-dependent to a calcium/calmodulin-inhibited kinase, with high activity in the absence of calcium, whereas autophosphorylation of the forebrain kinase results in a less active, calcium/calmodulin-independent enzyme. These properties of calmodulin kinase may play an important role in retinal function.

Ethics, technology, and the high cost of dying: a public forum

To increase public awareness of the complexity of the issues surrounding care for the terminally ill, a county medical society and a local hospital council co-sponsored a public forum in October 1985. Panel members discussed the case of a terminally ill cancer patient from the medical, psychologic, economic, legal, and family perspectives. Panel members stressed the importance of helping the dying person to choose the preferred treatment and to achieve an emotionally satisfying death. The audience responded by pointing out the barriers to achieving death with dignity, which include poverty, lack of social support, and difficulty in facing and talking about death. In an evaluation questionnaire, the audience indicated that the emotional aspects and the communication problems involved in care for the terminally ill caused them more concern than the legal and ethical issues.

Autophosphorylation of calmodulin kinase II: functional aspects

Autophosphorylation of purified calmodulin kinase II dramatically inhibited protein kinase activity and enhanced substrate selectivity. Inhibition was observed over a wide range of calmodulin concentrations but calmodulin binding was unaffected. Autophosphorylation of calmodulin kinase II may be a mechanism for limiting phosphorylation to physiological substrates and terminating some of calcium's actions in synaptic events.