Calcium binding of ARC mediates regulation of caspase 8 and cell death

Apoptosis repressor with CARD (ARC) possesses the ability not only to block activation of caspase 8 but to modulate caspase-independent mitochondrial events associated with cell death. However, it is not known how ARC modulates both caspase-dependent and caspase-independent cell death. Here, we report that ARC is a Ca(2+)-dependent regulator of caspase 8 and cell death. We found that in Ca(2+) overlay and Stains-all assays, ARC protein bound to Ca(2+) through the C-terminal proline/glutamate-rich (P/E-rich) domain. ARC expression reduced not only cytosolic Ca(2+) transients but also cytotoxic effects of thapsigargin, A23187, and ionomycin, for which the Ca(2+)-binding domain of ARC was indispensable. Conversely, direct interference of endogenous ARC synthesis by targeting ARC enhanced such Ca(2+)-mediated cell death. In addition, binding and immunoprecipitation analyses revealed that the protein-protein interaction between ARC and caspase 8 was decreased by the increase of Ca(2+) concentration in vitro and by the treatment of HEK293 cells with thapsigargin in vivo. Caspase 8 activation was also required for the thapsigargin-induced cell death and suppressed by the ectopic expression of ARC. These results suggest that calcium binding mediates regulation of caspase 8 and cell death by ARC.

Cysticercosis of cerebellopontine cistern: differential diagnosis using MRI

We report an example of subarachnoid neurocysticercosis located in the left cerebellopontine cistern of a 60 year-old man. The negative results of the serum and cerebrospinal fluid tests for parasites and the unusual MRI findings, such as the uncommon shape, location and extension pattern, made differential diagnosis difficult. Neurocysticercosis was confirmed by surgical and histopathological findings. The clinical and radiographic features of neurocysticercosis are highly variable. In an endemic area, neurocysticercosis should be considered in the differential diagnosis.

Effect of subthalamic lesion with kainic acid on the neuronal activities of the basal ganglia of rat parkinsonian models with 6-hydroxydopamine

The aim of the present study was to investigate the alteration of neuronal activities in the substantia nigra pars reticulata (SNpr) and globus pallidus (GP), after ipsilateral STN lesioning by kainic acid in the rat hemi-parkinsonian 6-hydroxydopamine (6-OHDA) model. In various rat Parkinson's disease (PD) models, an increase in the SNpr firing rate was observed, despite the occurrence of bursting patterns, and subthalamic lesion was found to reduce the mean firing rates and the percentage of bursting neurons in the SNpr. However, the relative proportion of bursting neurons, among all GP neurons, was slightly increased as a result of the subthalamic lesion. The significance of bursting activity in the SNpr and GP remains obscure. Further study is necessary to elucidate the pathophysiological mechanism behind Parkinson's disease.

Simple bone cyst occurring in calvarium

A 60 year-old female presented with a non-specific headache that she had experienced for 4 years. A simple skull X-ray indicated a well-defined, lobulated and radiolucent lesion with a thin sclerotic rim involving the parietal bone (Fig. 1A). Computed tomography revealed a hypodense lesion. Magnetic resonance imaging showed a 2 cm-sized cystic lesion in the diploic space with both tabular involvement. This lesion was not enhanced by contrast agent. It was well defined and the periosteum was intact. The cyst paralleled the CSF in signal intensity on all pulse sequences. No fluid levels were detected (Fig. 1B, C, D). After the scalp was incised, a semi-translucent and light yellow- to white-coloured bony lesion was easily identified. The outer bony cortex of this lesion was slightly elevated, and the consistency was same as that of the normal skull. A craniectomy was performed and the cystic skull lesion was removed. The inner surface of this cystic lesion was intact but appeared irregular. The cystic cavity was empty and the dura did not appear to be involved. Histologically, it was a simple cystic cavity without lining epithelium, and the surrounding bony structures were normal (Fig. 1E, F). It was diagnosed as a simple bone cyst (SBC). The postoperative course was uneventful.

Contribution of presenilin/gamma-secretase to calsenilin-mediated apoptosis

Mutant presenilins cause early-onset of familial Alzheimer's disease and render cells vulnerable to apoptosis. Calsenilin/DREAM/KChIP3 is a multifunctional calcium-binding protein that interacts with presenilin and mediates calcium-mediated apoptosis. In the present study, we report that the calsenilin-mediated apoptosis is regulated by presenilin. The expression of calsenilin was highly up-regulated in neuronal cells undergoing Abeta42-triggered cell death. The incidence of calsenilin-mediated apoptosis was diminished in presenilin-1(-/-) mouse embryonic fibroblast cells or neuronal cells stably expressing a loss-of-function presenilin-1 mutant. On the contrary, an array of familial Alzheimer's disease-associated presenilin mutants (gain-of-function) increased calsenilin-induced cell death. Moreover, gamma-secretase inhibitors, including compound E and DAPT, decreased the calsenilin-induced cell death. These results suggest that the pro-apoptotic activity of calsenilin coordinates with presenilin/gamma-secretase activity to play a crucial role in the neuronal death of Alzheimer's disease.

Down-regulation of ARC contributes to vulnerability of hippocampal neurons to ischemia/hypoxia

ARC is a caspase recruitment domain-containing molecule that plays an important role in the regulation of apoptosis. We examined ARC expression during neuronal cell death following ischemic injury in vivo and in vitro. After exposure to transient global ischemic conditions, the expression of ARC was substantially reduced in the CA1 region of hippocampus in a time-dependent manner with concomitant increase of TUNEL-positive cells. Quantitative analysis using Western blotting exhibited that most of ARC protein disappeared in the cultured hippocampal neurons exposed to hypoxia for 12 h and showing 60% cell viability. Forced expression of ARC in the primary cultures of hippocampal neurons or B103 neuronal cells significantly reduced hypoxia-induced cell death. Further, the C-terminal P/E rich region of ARC was effective to attenuate hypoxic insults. These results suggest that down-regulation of ARC expression in hippocampal neurons may contribute to neuronal death induced by ischemia/hypoxia.

Anterior cingulotomy for refractory obsessive-compulsive disorder

OBJECTIVE

This study was designed to prospectively investigate the efficacy and cognitive adverse effects of stereotactic bilateral anterior cingulotomy as a treatment for refractory obsessive-compulsive (OCD) patients for 12 months.

METHOD

Patients were eligible if they had severe OCD and rigorous treatments had been unsuccessful. Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Clinical Global Impression (CGI) and neuropsychological tests were used to assess the efficacy and cognitive changes of cingulotomy before and 12 months after operation.

RESULTS

The mean improvement rate of the Y-BOCS scores achieved from baseline was 36.0%. Out of 14 patients six met responder criteria; 35% or higher improvement rate on Y-BOCS and CGI improvement of very much or much better at 12-month follow-up. There was no significant cognitive dysfunction after cingulotomy.

CONCLUSION

Anterior cingulotomy shows few cognitive adverse effects, with about half of the OCD patients demonstrating significant symptomatic improvement.

Complications after gamma knife radiosurgery for benign meningiomas

OBJECTIVES

To analyse the results of gamma knife radiosurgery (GKS) for the treatment of intracranial meningiomas and to assess possible factors related to the outcome and complications of such treatment.

METHODS

The authors retrospectively reviewed the clinical and radiological data of 179 patients (194 lesions) treated with GKS for meningiomas between May 1992 and October 2000. The mean follow up duration was 37.3 months (range 6.4 to 86.3 months). The study determined the correlation between radiosurgical outcome including imaging changes after GKS and multiple factors such as tumour location and size, patient characteristics, venous sinus status, pre-GKS degree of oedema, other treatment modalities, and radiosurgical parameters.

RESULTS

The radiological control rate was 97.1%. Magnetic resonance imaging (MRI) showed complications after GKS in 35 lesions (25.0%) among the 140 lesions followed up with MRI. Complications were divided into peritumorous imaging changes (33 lesions; 23.6%) and transient cranial nerve dysfunction (two lesions; 1.4%). Radiation induced imaging changes were seen mostly in convexity, parasagittal, and falx meningiomas that were deeply embedded in the cortex. About 60% of these were asymptomatic and the overall rate of symptomatic imaging changes was 9.3%. Neurological deficit related to imaging changes developed in only three patients, and all the symptoms were transient.

CONCLUSION

GKS for intracranial meningiomas seems to be a safe and effective treatment. However, meningiomas of the convexity, parasagittal region, or falx cerebri have a higher incidence of peritumorous imaging changes after GKS than those of the skull base. Therefore, the use of GKS needs to be considered very cautiously in cerebral hemispheric meningiomas, taking into consideration patient age and general condition, tumour size and location, pattern of cortical embedding, relation between the tumour and venous sinuses, presenting symptoms, and patient preference.

Neurophysiological identification and characterization of thalamic neurons with single unit recording in essential tremor patients

This study investigated the characteristics of the neuronal activities of the motor thalamus (Vim and Vop) in essential tremor (ET) patients, and compared the results with those of Parkinson's disease (PD) patients. The kinetic (Ki) neurons were found mainly in the Vim, whereas the voluntary (Vo) neurons were found principally in the Vop of ET patients. The mean firing rates of the ET patients were higher than those of the PD patients. In addition, the mean firing rates of the Ki neurons of the ET patients were higher than those of the PD patients in the Vim nuclei. However, the mean firing rates of the ventralis caudalis (Vc) neurons, which respond to sensory stimulation, were similar in each group. An analysis of the incidence of bursting neurons revealed that the Vop nucleus of the ET patients had less bursting neurons than the PD patients. However, in the Vim nucleus, both groups possessed bursting neurons even though the incidence was slightly different. Tremor cells were observed less frequently in the Vim nucleus of ET patients than in the PD patients. This study demonstrated the characteristic features of the neuronal activities of ET patients compared to those of PD patients.

Microvascular decompression for hemifacial spasm: a long-term follow-up of 1,169 consecutive cases

We analyzed the records of 1,169 patients with hemifacial spasm (HFS) who underwent microvascular decompression (MVD) and were followed up for more than 6 months from January 1987. The mean follow-up duration was 23.8 months (6-145 months). Excellent surgical outcome was obtained in 90.5% and good in 4.5%, giving an overall success rate of 95.0%. There was statistically significant relationship between vertebral artery (VA) shift and side of symptom. Permanent facial weakness and hearing impairment were 1.4% and 2.3%, respectively. There were no anatomical differences at the root entry zone (REZ) and significant differences of surgical outcome in young HFS (34 patients). Factors such as type of offender, severity of compression on the facial nerve root, and the degree of decompression of the REZ on postoperative MRI did not correlate with surgical outcome.

Gamma knife radiosurgery for metastatic brain tumors

We reviewed our series of metastatic brain tumors treated by Gamma Knife Radiosurgery. From May 1992 to January 2001, 115 consecutive patients with 425 lesions were treated over 128 treatment sessions. Forty three patients were known to have died at the end of the recording period. The mean follow-up duration was 11.6 months and mean number of lesions was 3.5. The most common primary sites were lung and breast. Mean tumor volume was 4.2 cm(3) and mean margin dose was 16.2 Gy. 6-month, 1-year, and 18-month survival rates were 73.6, 58, and 46%, respectively. Multivariate analysis revealed that higher KPS scores, no evidence of extracranial metastasis, and controlled primary disease were significantly related to longer survival. Adjuvant whole brain irradiation did not significantly influence on the prolongation of survival time and local control of radiosurgically treated lesions.

Unilateral globus pallidus internus stimulation improves delayed onset post-traumatic cervical dystonia with an ipsilateral focal basal ganglia lesion

Treatment with unilateral left globus pallidus internus (GPi) deep brain stimulation is reported in a patient with severe delayed onset post-traumatic cervical dystonia. He had sustained severe head trauma at the age of 17 and had developed a mild right hemiparesis. Three years after the head injury, cervical dystonia with head turning to the left side developed. Magnetic resonance imaging (MRI) showed a discrete GPi lesion on the left side. At the age of 23, he underwent unilateral left GPi deep brain stimulation. He experienced immediate but short lasting benefit from the microlesioning effect of the electrode. With activation of deep brain stimulation, there was significant improvement of the cervical dystonia, persisting for 12 months of follow up. This case underlines the importance of the globus pallidus internus in the generation and amelioration of cervical dystonia.

A site-specific mutation of tyrosine hydroxylase reduces feedback inhibition by dopamine in genetically modified cells grafted in parkinsonian rats

Aromatic L-amino acid decarboxylase (AADC) is necessary for conversion of L-DOPA to dopamine. Therefore, AADC gene therapy has been proposed to enhance pharmacological or gene therapies delivering L-DOPA. However, addition of AADC to the grafts of genetically modified cells expressing tyrosine hydroxylase (TH) and GTP cyclohydrolase 1 (GCH1), which produce L-DOPA in parkinsonian rats, resulted in decreased production of L-DOPA and dopamine owing to feedback inhibition of TH by dopamine. End-product feedback inhibition has been shown to be mediated by the regulatory domain of TH, and site-specific mutation of serine 40 makes TH less susceptible to dopamine inhibition. Therefore, we investigated the efficacy of using TH with serine 40 mutated to leucine (mTH) in an ex vivo gene-therapy paradigm. Primary fibroblasts (PF) from Fischer 344 rats were transduced with retrovirus to express mTH or wild-type rat TH cDNA (wtTH). Both cell types were also transduced with GCH1 to provide the obligate TH cofactor, tetrahydrobiopterin. PF transfected with AADC were used as coculture and cografting partners. TH activities and L-DOPA production in culture were comparable between PFwtTHGC and PFmTHGC cells. In cocultures with PFAADC cells, PFmTHGC cells showed significant reduction in the inhibitory effect of dopamine compared with PFwtTHGC cells. In vivo microdialysis measurement showed that cografting PFAADC cells with PFmTHGC cells resulted in smaller decreases in L-DOPA and no reduction in dopamine levels compared with cografts of PFAADC cells with PFwtTHGC cells, which decreased both L-DOPA and dopamine levels. Maintenance of dopamine levels with lower levels of L-DOPA would result in more focused local delivery of dopamine and less potential side-effects arising from L-DOPA diffusion into other structures. These data support the hypothesis that mutation of serine 40 attenuates TH end-product inhibition in vivo and illustrates the importance of careful consideration of biochemical pathways and interactions between multiple genes in gene therapy.

The role of inducible nitric oxide synthase in aseptic loosening after total hip arthroplasty

We collected 16 samples of the membrane which surrounds loose hip prostheses from patients undergoing revision operations for aseptic loosening. To serve as the control group, samples of the synovial tissue and the fibrous capsular tissue were collected from 11 patients undergoing primary hip arthroplasties. Analyses of the expression levels of inducible nitric oxide synthase (iNOS), tumour necrosis factor-alpha (TNF-alpha), and cytosolic phospholipase A2 (cPLA2) mRNAs were performed by a reverse transcription polymerase chain reaction, and the content of nitrite was measured by the Griess reaction using sodium nitrite as the standard. The expression levels of iNOS, TNF-alpha, and cPLA2 mRNAs in the membranes were significantly higher than those in the control samples (p < 0.05). The expression levels of iNOS mRNA and the nitrite content in the membranes significantly correlated with those of TNF-alpha and cPLA2 mRNAs, respectively. In addition, the expression levels of iNOS, TNF-alpha, and cPLA2 mRNAs were significantly higher in membranes from cementless than in those from cemented implants (p < 0.05). Our results suggest that the expression levels of iNOS, TNF-alpha, and cPLA2 mRNAs in the membranes are regulated by closely-related mechanisms and that these have a significant role in aseptic loosening.

Ictal electrocorticographic findings related with surgical outcomes in nonlesional neocortical epilepsy

PURPOSE

To characterize ictal electrocorticographic features related to surgical outcomes in nonlesional neocortical epilepsy (NE).

METHODS

We analyzed 187 ictal electrocorticograms (ECoG) obtained from 18 patients who had undergone presurgical evaluation and subsequent neocortical resections (frontal: seven, parietal: one, occipital: four, multilobar: six). None of them had any MRI-detectable lesions. Various ECoG data sets recorded from eight patients who achieved a favorable surgical outcome (either seizure free or more than 90% reduction of seizure frequencies) were compared with that from ten patients with unfavorable outcome (less than 90% reduction of seizure frequencies) (follow up duration: 47+/-11 months).

RESULTS

Reproducible ictal onset zone (IOZ) in recurrent seizures (P=0.013) and persistent ictal discharges in IOZ from the onset to the end of seizure (P=0.004) were found more frequently in the patients with good outcome. Ictal onset patterns consisting of low voltage fast or high amplitude beta spikes predicted a good surgical outcome while rhythmic sinusoidal activity or rhythmic spike/sharp waves of slow frequency were predictive of poor outcome (P=0.01). The ictal onset rhythm consisting of gamma or beta frequencies was more prevalent in the favorable group (P=0.015).

CONCLUSIONS

The presence of stable ictal circuit suggested by the consistent earliest activation of specific electrodes in the repetitive seizures (reproducible IOZ) and the active participation of IOZ throughout the attack were valuable prognostic factors in addition to the morphology and frequency of ictal onset rhythm.

Radiologically confirmed de novo glioblastoma multiforme and hippocampal sclerosis associated with the first onset of nonconvulsive simple partial status epilepticus

The authors report a case of an unusual progression of glioblastoma multiforme in the temporal lobe associated with the first onset of nonconvulsive simple partial status epilepticus (SPSE), a rare form of status epilepticus. The patient underwent a left temporal craniotomy and the tumor was removed. Concurrently, the hippocampus was removed as well. The pathological diagnosis of the tumor and the hippocampus were glioblastoma multiforme and hippocampal sclerosis. The patient's postoperative course was uneventful.

Synthesis of substituted-(l)-tryptophanols from an enantiomerically pure aziridine-2-methanol

Enantiomerically pure (l)-tryptophanol (5) was synthesized from 4(R)-iodomethyl-2-oxazolidinone (2) and indolylmagnesium bromide in three steps (52% overall yield). Using this procedure, we also prepared various tryptophanols with substituent(s) on the indole ring. Furthermore, optically active 4(R)-iodomethyl-2-oxazolidinone was readily prepared from an enantiomerically pure aziridine-2(S)-methanol in high yield. [reaction: see text]

The efficacy and safety of risperidone for the treatment of geriatric psychosis

Risperidone is an atypical antipsychotic drug which has been suggested to be beneficial for the treatment of elderly patients with psychotic symptoms. In this study, we assessed the short-term efficacy and the safety of risperidone in geropsychiatric inpatients with psychotic symptoms. The sample population included 110 elderly inpatients with psychotic disorders. Assessment for drug efficacy using the Brief Psychiatric Rating Scale, Sandoz Clinical Assessment-Geriatric scale, and Clinical Global Impression scale was conducted at baseline and also at 4 weeks subsequent to risperidone treatment commencement. Subsequent to commencing risperidone treatment, 80 patients completed a 4-week therapeutic evaluation. Seventy (87.5%) of the 80 patients experienced mild to substantial improvement using the Clinical Global Impression scale. Adverse effects were monitored in all 110 patients. The most commonly detected adverse effects were weakness of legs or walking problems (43/110; 39.1%) and dizziness (32/110; 29.1%). Peripheral edema was noted in 18 (16.4%) patients. Risperidone, in low doses, appeared to have been effective in this sample of patients older than 65 years with psychotic symptoms. The mean dose (2.1 +/- SD 1.4 mg/day) applied was lower then that suggested for young patients and was related to the each specific patient diagnosis. Peripheral edema and walking problems were commonly observed adverse effects for these elderly patients, such problems having not been seen to the same extent in previous studies of young patients.

Augmented expression of peroxiredoxin I in lung cancer

Comparative proteome analysis was performed between human normal (BEAS 2B) and malignant (A549) lung epithelial cells in an attempt to identify novel biomarkers of lung cancer. Approximately 500 protein spots could be separated by mini two-dimensional electrophoresis and visualized with Coomassie blue R-250. Among those relatively abundant proteins, eight spots were changed more than twofold reproducibly and identified by peptide mass fingerprints using mass spectrometry and database search. The increased proteins in A549 were aldehyde dehydrogenase, peroxiredoxin I, fatty acid binding protein, aldoketoreductase, and destrin, whereas the decreased proteins were galectin-1, transgelin, and stathmin. Since human lung is exposed to continuous oxidative stress, antioxidant enzyme peroxiredoxin I was selected for further investigation and its augmented expression was confirmed in cancer tissues compared to normal tissues from lung cancer patients, suggesting peroxiredoxin I as a potential biomarker of lung cancer.

Two-dimensional gel analysis of secreted proteins induced by interleukin-1 beta in rat astrocytes

Interleukin-1 beta (IL-1 beta) is a pro-inflammatory cytokine produced in the brain by endogenous microglial cells responding to injury. Levels of IL-1 beta are elevated in several neurodegenerative disorders, including Alzheimer's disease. IL-1 beta, which can act as a mitogen for astrocytes, also elicits the expression and secretion of multiple factors and paracrine 'second messengers' such as other cytokines, nerve growth factor, prostaglandins and nitric oxide that may in turn modulate neuronal and glial responses to injury. Utilizing giant, high-resolution two-dimensional gel electrophoresis, we have sought to more fully define the potential range of protein mediators that are secreted by astrocytes treated with IL-1 beta. In cultured rat astrocytes, we observe dramatic increases in the secretion of eight different protein species after 24 h of treatment with human recombinant IL-1 beta (1 U/ml). Seven of the proteins are also induced by tumor necrosis factor-alpha or basic fibroblast growth factor. Based on immunoprecipitation with specific antisera, we have identified three of these proteins as plasminogen activator inhibitor type-1, ceruloplasmin, and complement component C3. The identities of the other proteins, including the IL-1 beta-specific induction, are currently unknown. Characterization of these downstream modulators of IL-1 beta action complements gene-based approaches and will provide a better understanding of astrocyte responses to injury as well as markers for astrocyte activation in neurodegenerative diseases.

Characteristics of Chinese suicide attempters admitted to a geropsychiatric unit

PURPOSE

To investigate the characteristics for elderly Chinese suicide attempters in Taiwan and make comparisons with Western reports.

METHODS

During a six-year period, patients admitted to a geropsychiatric unit as a result of a suicide attempt were investigated for factors related to the suicide attempt.

RESULTS

Of the 722 admissions during this period, 55 (7.6%) were patients who had been admitted due to suicide attempt. The sex and age distributions for the suicide attempters were similar to those for other patients. The most common diagnoses were depressive disorders (56.4%), followed by delusional disorders (20.0%). A total of 121 suicide motives were cited for the 55 attempters, an average of 2.2 per person, with depressive symptoms commonly found on admission. During the first week of hospitalization, 53 attempters (96.4%) still exhibited suicidal ideation and six patients made a further suicide attempt, however, only three patients retained suicidal ideation on discharge.

CONCLUSIONS

Our study confirms previous Western reports that depressive disorders are commonly manifested in elderly suicide attempters. There were differences in the motives and methods employed for the suicides, possibly due to cultural difference and/or sample source. Most of the suicide attempters exhibited a favourable response with hospitalization.

Outcome of renal transplantation in hepatitis B surface antigen-positive patients after introduction of lamivudine

BACKGROUND

In end-stage renal disease patients with hepatitis B surface antigen (HBsAg), the risk of hepatic dysfunction after immunosuppression represents a large barrier in renal transplantation. Lamivudine is a potent inhibitor of hepatitis B virus (HBV) replication. We retrospectively investigated the outcome of HBsAg-positive renal transplantation recipients after lamivudine had become available.

METHODS

From July 1994 to August 2000, seventeen HBsAg-positive patients (M:F=15:2) received renal allografts (13:4=living:cadaveric donors). Liver function tests at the time of transplantation were normal in all patients. Pre-transplant liver biopsies performed in 15 patients demonstrated minimal inflammatory histology, except in three patients showing pathological and clinical signs of active hepatitis. Lamivudine was started pre-operatively in these three subjects. Another seven patients were treated with lamivudine for post-operative hepatic dysfunction. The remaining seven patients did not develop hepatic dysfunction after transplantation.

RESULTS

Lamivudine was initially effective in decreasing serum HBV DNA titres, and in normalizing hepatic enzymes. Lamivudine was well tolerated without significant side effects for 35.5+/-8.9 months after initiation of treatment. HBV DNA became negative in nine patients but remained positive in one patient. Among the nine patients with initial negative conversion of HBV DNA, two developed transient positive conversion of HBV DNA and two demonstrated persistent positive conversion. Among the patients with normal liver histology in the pre-transplant period, 41.6% (5/12) developed liver pathology progression after immunosuppression. All 17 patients had functioning grafts, except for one patient who developed relapsed IgA nephropathy.

CONCLUSIONS

Our data showed relatively favourable outcomes in hepatitis B-positive renal transplant recipients receiving lamivudine treatment, even though two patients developed lamivudine resistance.

Rudimentary TCR signaling triggers default IL-10 secretion by human Th1 cells

Understanding the process of inducing T cell activation has been hampered by the complex interactions between APC and inflammatory Th1 cells. To dissociate Ag-specific signaling through the TCR from costimulatory signaling, rTCR ligands (RTL) containing the alpha1 and beta1 domains of HLA-DR2b (DRA*0101:DRB1*1501) covalently linked with either the myelin basic protein peptide 85-99 (RTL303) or CABL-b3a2 (RTL311) peptides were constructed to provide a minimal ligand for peptide-specific TCRs. When incubated with peptide-specific Th1 cell clones in the absence of APC or costimulatory molecules, only the cognate RTL induced partial activation through the TCR. This partial activation included rapid TCR zeta-chain phosphorylation, calcium mobilization, and reduced extracellular signal-related kinase activity, as well as IL-10 production, but not proliferation or other obvious phenotypic changes. On restimulation with APC/peptide, the RTL-pretreated Th1 clones had reduced proliferation and secreted less IFN-gamma; IL-10 production persisted. These findings reveal for the first time the rudimentary signaling pattern delivered by initial engagement of the external TCR interface, which is further supplemented by coactivation molecules. Activation with RTLs provides a novel strategy for generating autoantigen-specific bystander suppression useful for treatment of complex autoimmune diseases.

Ictal automatisms with preserved responsiveness in a patient with left mesial temporal lobe epilepsy

PURPOSE

To describe the possible mechanism of ictal automatisms with preserved responsiveness (APRs) in a patient with left mesial temporal lobe epilepsy, which had not been reported previously.

METHODS

Ictal EEGs recorded from bilateral foramen ovale electrodes with scalp-sphenoidal electrodes were analyzed in respect to the ictal semiology.

RESULTS

The patient had a right hemispheric language dominance in the dextral. Electroclinical analysis revealed that the onset of oroalimentary automatisms coincided with the involvement of the left mesial and lateral temporal structures by spreading ictal discharges. The ictal discharge spreading was limited to the ipsilateral hemisphere throughout the seizure, which explained the intact consciousness and preserved responsiveness of the patient.

CONCLUSIONS

This case suggests that APRs take place in seizures originating from the nondominant temporal lobe, during which ipsilateral mesial and lateral temporal structures are diffusely involved without spreading to the contralateral side.

Microvascular decompression in trigeminal neuralgia: a correlation of three-dimensional time-of-flight magnetic resonance angiography and surgical findings

We analyzed 104 patients with trigeminal neuralgia who underwent microvascular decompression and who were followed up for more than 12 months during the period from January 1992 to June 1998. In this recent series, we utilized three-dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA) for all patients with trigeminal neuralgia. A 3D-TOF MRA was beneficial in treatment planning and in predicting surgical outcome by demonstrating cranial nerve compression as well excluding other etiologies such as tumor or vascular lesions. The patients were followed up for 1-7 years (mean 5.7 +/- 1.2 years). Initial pain relief was complete in 89 patients (85.6%) and partial in 12 patients (11.5%). There were three primary failures (2.9%). The acceptable pain relief rate (complete relief: 79.8%, partial relief: 11.5%) was determined in the long-term follow-up of surgical results. Pain recurred in 6 patients (5.8%). The mean time to recurrence was 48 months (36-93 months). There were no serious or annoying complications such as anesthesia dolorosa.