Clinical course, imaging, and pathological features of 45 adult and pediatric cases of myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described neuroinflammatory demyelinating disease.

OBJECTIVE

To better understand the clinical spectrum, risk factors and outcomes in MOGAD.

METHODS

Retrospective cohort study including all subjects harboring anti-MOG antibodies identified in major academic hospitals across the province of Quebec.

RESULTS

We identified 45 MOGAD cases. The minimal estimated point-prevalence was 0.52/100 000 in Quebec. Median age at presentation was 32 years (range 1-71) with equal sex ratio. Most frequent ethnic groups were Caucasians and Asians. The most frequent clinical manifestations at onset were optic neuritis (ON), affecting 56% of adults, and acute disseminated encephalomyelitis (ADEM), affecting 33% of children. First MRI was abnormal in 84% of cases. Most CSF samples showed pleocytosis without oligoclonal bands. Two brain biopsies revealed lipid-laden macrophages and reactive astrocytes. Despite steroids, only 38% had fully recovered at 4 weeks after onset. Half of pediatric and two thirds of adult-onset MOGAD subjects experienced relapses. At last follow-up, 69% showed residual deficits, which were moderate to severe in 17% of adults.

CONCLUSION

MOGAD has heterogeneous disease course, and it is not a benign disease for a substantial proportion of adults. Best disease-modifying therapies remain to be determined.

145 Long-term safety of ofatumumab in patients with relapsing multiple sclerosis

Objective

To assess the long term safety and tolerability of ofatumumab treatment in patients with relapsing multiple sclerosis (RMS)

Methods

Patients completing the core ASCLEPIOS I/II, APOLITOS and APLIOS trials could enter ALITHIOS, an ongoing, open-label, extension trial. Here, we analyze the cumulative data for up to 4 years of ofa- tumumab treatment (data cutoff: 25-Sep-2021) in the overall (N=1969), continuous (ofatumumab in core+extension; N=1292) and newly-switched (teriflunomide core and ofatumumab extension; N=677) groups. Laboratory parameters including neutrophils, lymphocytes, and serum immunoglobulin (Ig) G and IgM levels will be analyzed.

Results

In data reported from ALITHIOS (cut-off of 29-Jan-2021), representing ofatumumab treatment for up to ~3.5 years, 83.8% of patients had ≥1 AEs (exposure-adjusted incidence rate [EAIR], 148.7) and 9.7% had ≥1 serious AEs (EAIR, 4.8) with a low incidence of serious infections (2.9%; EAIR, 1.4) and malignancies (0.3%; EAIR, 0.3). Updated safety data representing continuous ofatumumab treatment for up to 4 years will be presented at the congress.

Conclusion

Safety findings for up to 3.5 years show ofatumumab treatment to be generally well-tol- erated with no new safety risks identified. This additional safety data will help confirm ofatumumab’s longer-term safety profile. Funding: Novartis Pharma AG, Basel, Switzerland.

Comparison of switching to 6-week dosing of natalizumab versus continuing with 4-week dosing in patients with relapsing-remitting multiple sclerosis (NOVA): a randomised, controlled, open-label, phase 3b trial

BACKGROUND

Treatment with natalizumab once every 4 weeks is approved for patients with relapsing-remitting multiple sclerosis, but is associated with a risk of progressive multifocal leukoencephalopathy. Switching to extended-interval dosing is associated with lower progressive multifocal leukoencephalopathy risk, but the efficacy of this approach is unclear. We aimed to assess the safety and efficacy of natalizumab once every 6 weeks compared with once every 4 weeks in patients with relapsing-remitting multiple sclerosis.

METHODS

We did a randomised, controlled, open-label, phase 3b trial (NOVA) at 89 multiple sclerosis centres across 11 countries in the Americas, Europe, and Western Pacific. Included participants were aged 18-60 years with relapsing-remitting multiple sclerosis and had been treated with intravenous natalizumab 300 mg once every 4 weeks with no relapses for at least 12 months before randomisation, with no missed doses in the previous 3 months. Participants were randomly assigned (1:1), using a randomisation sequence generated by the study funder and contract personnel with interactive response technology, to switch to natalizumab once every 6 weeks or continue with once every 4 weeks. The centralised MRI reader, independent neurology evaluation committee, site examining neurologists, site backup examining neurologists, and site examining technicians were masked to study group assignments. The primary endpoint was the number of new or newly enlarging T2 hyperintense lesions at week 72, assessed in all participants who received at least one dose of assigned treatment and had at least one postbaseline MRI, relapse, or neurological examination or efficacy assessment. Missing primary endpoint data were handled under prespecified primary and secondary estimands: the primary estimand included all data, regardless of whether participants remained on the assigned treatment; the secondary estimand classed all data obtained after treatment discontinuation or study withdrawal as missing. Safety was assessed in all participants who received at least one dose of study treatment. Study enrolment is closed and an open-label extension study is ongoing. This study is registered with EudraCT, 2018-002145-11, and ClinicalTrials.gov, NCT03689972.

FINDINGS

Between Dec 26, 2018, and Aug 30, 2019, 605 patients were assessed for eligibility and 499 were enrolled and assigned to receive natalizumab once every 6 weeks (n=251) or once every 4 weeks (n=248). After prespecified adjustments for missing data, mean numbers of new or newly enlarging T2 hyperintense lesions at week 72 were 0·20 (95% CI 0·07-0·63) in the once every 6 weeks group and 0·05 (0·01-0·22) in the once every 4 weeks group (mean lesion ratio 4·24 [95% CI 0·86-20·85]; p=0·076) under the primary estimand, and 0·31 (95% CI 0·12-0·82) and 0·06 (0·01-0·31; mean lesion ratio 4·93 [95% CI 1·05-23·20]; p=0·044) under the secondary estimand. Two participants in the once every 6 weeks group with extreme new or newly enlarging T2 hyperintense lesion numbers (≥25) contributed most of the excess lesions. Adverse events occurred in 194 (78%) of 250 participants in the once every 6 weeks group and 190 (77%) of 247 in the once every 4 weeks group, and serious adverse events occurred in 17 (7%) and 17 (7%), respectively. No deaths were reported. There was one case of asymptomatic progressive multifocal leukoencephalopathy (without clinical signs) in the once every 6 weeks group, and no cases in the once every 4 weeks group; 6 months after diagnosis, the participant was without increased disability and remained classified as asymptomatic.

INTERPRETATION

We found a numerical difference in the mean number of new or newly enlarging T2 hyperintense lesions at week 72 between the once every 6 weeks and once every 4 weeks groups, which reached significance under the secondary estimand, but interpretation of statistical differences (or absence thereof) is limited because disease activity in the once every 4 weeks group was lower than expected. The safety profiles of natalizumab once every 6 weeks and once every 4 weeks were similar. Although this trial was not powered to assess differences in risk of progressive multifocal leukoencephalopathy, the occurrence of the (asymptomatic) case underscores the importance of monitoring and risk factor consideration in all patients receiving natalizumab.

FUNDING

Biogen.

Book Review: Neurology in Clinical Practice

N/A

Abstract P4-01-19: Liquid biopsy and re-biopsy: Tracking mutational trajectories in HER2+ breast cancer patients undergoing T-DM1 treatment

Background: The antibody-drug conjugate Trastuzumab emtansine (T-DM1, Kadcyla®) is standard of care in HER2+ breast cancer patients on clinical progression after Trastuzumab/Pertuzumab and taxanes. Despite considerable clinical benefits, most patients rapidly develop progressive disease due to adaptive resistance, the molecular bases of which remain largely unknown and/or controversial. Next generation sequencing (NGS) and digital PCR (dPCR) applied to serial biological samples obtained through liquid biopsy (LB) and re-biopsy (RB) offer a unique opportunity to intercept mutational trajectories and uncover molecular patterns linked to primary as well as adaptive resistance.

Materials and methods: Tumor tissues (n=14), either from primary or metastatic lesions, and plasma samples (n=99) were collected, upon informed consent, from 9 breast cancer patients undergoing T-DM1 administration. Tissue (tDNA) and circulating tumor DNA (ctDNA) were extracted by the QIAmp DNA FFPE and CNA kits (Qiagen), respectively, and analyzed by ultra-deep sequencing and dPCR (IonTorrent S5 and QuantStudio 3D, LifeTechnologies) with commercial 400-gene panel and custom-designed dPCR assays. Genomic data were correlated with clinical imaging (CT/PET).

Results: Six out 9 (66.7%) patients experienced progression within 1 year of treatment (mean 192±97 days), whereas the remaining 3 were stable at the last follow up (> 400 days). No correlation was found between outcome and HER2, ER or PR status in the latest available (prior to T-DM1) archival tissue, in which NGS revealed several pre-existing mutations, including some associated with resistance to ERBB2 blockade. LB analysis detected increases in both baseline and de novo occurring aberrations in 5/6 (83.4%) relapsing patients. As compared to clinical imaging, progression disease was anticipated by an average lead time of 1.9 months (range 0.7-2.8). Surprisingly, the sixth relapsing patient underwent rapid progression (3 months) in spite of decreased PIK3CA p.E545K in blood, further confirmed in the re-biopsy, thus suggesting heterogeneous response to T-DM1 across multiple cancer cell populations. Of note, we observed progressive accumulation of ERBB2 p.L755S (associated with Lapatinib resistance) in multiple biopsies of serial metastatic foci from a patient over 18 years of multimodal ERBB2 blockade. However, a single administration of T-DM1 resulted in ultra-fast (within few weeks) clearance of ERBB2 p.L755S ctDNA, and stabilization of two distinct 'bystander' TP53 ctDNAs (p.R273H and p.S241T).

Conclusions: Non-invasive LB monitoring of a small cohort of T-DM1-treated patients provides proof of principle of intersecting mutational trajectories, anticipation and classification of resistance, as well as de novo appearance/clearance of resistance mutations. Thus, LB and RB may hint at disease evolution and successive lines of medical treatment.

This work was supported by AIRC (Nuvenia Fellowship to MA, IG 19052 to PG), EU commission (grant #633937 – ULTRAPLACAD), and Regina Elena National Cancer Institute intramural funding.

Citation Format: Allegretti M, Giordani E, Casini B, Romania P, Gasparro S, Russillo M, Gallo E, Buglioni S, Pescarmona E, Cognetti F, Ciliberto G, Giacomini P, Fabi A. Liquid biopsy and re-biopsy: Tracking mutational trajectories in HER2+ breast cancer patients undergoing T-DM1 treatment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-19.

Sapienza Global Bedside Evaluation of Swallowing after Stroke: the GLOBE-3S study

BACKGROUND AND PURPOSE

Dysphagia occurs in up to 50% of all patients with acute stroke. There is debate regarding which is the most effective screening tool in identifying aspiration in patients with acute stroke. We assessed the accuracy of the Sapienza Global Bedside Evaluation of Swallowing after Stroke (GLOBE-3S), which combines the Toronto Bedside Swallowing Screening Test (TOR-BSST©) with oxygen desaturation and laryngeal elevation measurement during swallowing.

METHODS

We prospectively enrolled consecutive patients with stroke within 72 h of symptom onset. All patients with stroke firstly underwent a standard neurological examination, then the GLOBE-3S evaluation and finally the fiberoptic endoscopic evaluation of swallowing (FEES). Two different assessors, a neurologist and a speech pathologist, blind to both the clinical data and each other's evaluation, administered the GLOBE-3S and FEES examination. We assessed the accuracy of the GLOBE-3S in detecting post-stroke swallow impairment with aspiration using the FEES as the standard.

RESULTS

We enrolled 50 patients with acute stroke, 28 of whom (56%) had swallowing impairment with aspiration at FEES evaluation. A total of 33 patients (66%) failed the GLOBE-3S evaluation. The GLOBE-3S reached a sensitivity of 100% and a specificity of 77.3% (negative predictive value, 100%; positive likelihood ratio, 4.34). The median time required for the GLOBE-3S to be performed was 297 s.

CONCLUSIONS

GLOBE-3S is quick to perform at the bedside and can accurately identify aspiration in patients with acute stroke. By including the measurement of laryngeal elevation and monitoring of oxygen desaturation, it could represent a highly sensitive instrument to avoid the misdiagnosis of silent aspirators.

Methylation State of Cellular Genes and Oncogenes as a Marker of Malignancy in Human Carcinomas

The methylation pattern of the human HLA-DRα gene was analyzed in primary tumors and lymph node metastases isolated from patients with a variety of tumors, including thyroid, pancreas, breast and gastric carcinomas and melanomas. In normal tissues (including breast, muscle, brain, sperm, T-and B-lymphocytes) the HLA-DRα gene is hypermethylated at CCGG and GCGC sites. In all tissues studied, the only constantly unmethylated region was located in the 5′ portion of the gene. Our results indicate that the HLA-DRα gene is hypomethylated in metastatic lymph nodes, as well as in the carcinomas and melanomas studied. These findings lend support to the hypothesis that DNA hypomethylation of the human HLA-DRα gene may represent a molecular marker of malignant tumors.

Molecular Profile, Tissue Distribution and Prognostic Evaluation of a Human Melanoma-Carcinoma Antigen Recognized by the Murine Monoclonal Antibody B1.1

Using the murine monoclonal antibody (MoAb) B1.1 we have analyzed the immunochemical profile and the tissue distribution of a human melanoma associated antigen (MAA) carrying an epitope shared by the 180 kd CEA. Results of this study have demonstrated that the epitope expressed by the MAA is carried by a distinct set of molecules of 110-140 kd. Similarly to the 180 kd CEA molecules synthesized by carcinomas, the expression of the melanoma associated CEA like components (MA-CEA) is upregulated by IFN-α. The tissue distribution of MA-CEA is not restricted to malignant primary and metastatic melanocytic lesions but is found also at low levels in 64% of benign nevi. No circulating CEA was found in patients bearing widespread metastatic disease of MA-CEA positive lesions.

Preliminary clinical evaluation of stage I melanoma patients bearing MoAb Bl. l positive lesions has not shown a significative prognostic association of this phenotypic marker with clinical course of the disease.

A Comparison of the Cyclic Anhydride and Mixed Anhydride Methods for 111In-DTPA Chelation to Monoclonal Antibodies

The cyclic anhydride (CA) and the mixed anhydride (MA) of DTPA were synthesized and used to chelate 111In to an antimelanoma monoclonal antibody. The CA and MA methods showed mean labeling efficiencies of 25.7 and 20.5%, respectively (p = NS). The binding efficiency of labeled antibody to human melanoma cells in tissue culture also was similar (x̄ = 52 and 50%, respectively, p = NS), as was tumor uptake in nude mice at 96 hrs post-injection (16%-CA vs 12%-MA). The method required less complicated chemical syntheses, much less preparation time, and the product was stable over a much longer period. The results suggest that the CA method is preferable for bifunctional chelate labeling of monoclonal antibodies with 111In-DTPA.

Major histocompatibility complex class i and tumour immuno-evasion: how to fool T cells and natural killer cells at one time

Cytotoxic T lymphocytes (ctls) and natural killer (nk) cells lyse tumours expressing and lacking, respectively, properly conformed class i molecules of the major histocompatibility complex [mhc-i (Figure 1)] [...]

Unknown primary tumors

An unknown primary tumor (UPT) is defined by the presence of a metastatic cancer without a known primary site of origin despite a standardized diagnostic workup. Clinically, UPTs show rapid progression and early dissemination, with signs and symptoms related to the metastatic site. The molecular bases of their biology remain largely unknown, with no evidence as to whether they represent a distinct biological entity. Immunohistochemistry remain the best diagnostic tool in term of cost-effectiveness, but the time-consuming "algorithmic process" it relies on has led to the application of new molecular techniques for the identification of the primary site of UPTs. For example, several microarray or miRNA classifications of UPTs have been used, with an accuracy in the prediction of the primary site as high as 90%. It should be noted that validating a prediction of tissue origin is challenging in these patients, since most of them will never have a primary site identified. Moreover, prospective studies to determine whether selection of treatment options based on such profiling methods actually improves patient outcome are still missing. In the last few years functional imaging (i.e. FDG-PET/CT) has gained a main role in the detection of the site of origin of UPTs and is currently recommended by the European Association of Nuclear Medicine. However, despite recent refinements in the diagnostic workup, the site of origin of UPT often remains elusive. As a consequence, treatment of patients with UPT is still empirical and inadequate.

Gene variants associated to malignant thyroid disease in familial adenomatous polyposis: a novel APC germline mutation

BACKGROUND AND AIM

Familial adenomatous polyposis (FAP) is an autosomal inherited syndrome characterized by hundreds to thousands colorectal adenomatous polyps with oncological transformation lifetime risk of 100%. FAP is mainly associated with mutations in APC (autosomal dominant inheritance) or MUTYH (autosomal recessive inheritance) genes. Affected individuals are at increased risk of developing extra-intestinal tumors. Lifetime risk of developing thyroid carcinoma has been described in previous reports of about 2-12%, mainly in females, and the mean age is below 30 yr. About 95% of cancers are papillary thyroid carcinomas (PTC), mostly multifocal. The aim of this study was to evaluate the frequency of PTC among our series of FAP patients and to assess the type of gene mutation associated with the disease.

METHODS

Fifty-four subjects from 36 FAP families were selected (29 females/25 males) and the mean age (±SD) at diagnosis was 28.8±10.8 yr. All patients underwent blood examination for thyroid hormones and antibodies, germline mutational analysis of APC and/or MUTYH genes, thyroid ultrasound, and endocrinological evaluation.

RESULTS

In 13/54 (24.1%) subjects, an eumetabolic thyroid disease was found: plurinodular disease in 7/54 (13.0%); single nodule in 4/54 (7.4%); in 2/54 patients (3.7%), we found a malignant nodule characterized after total thyroidectomy as a classical PTC. Both patients were female and showed a classic FAP phenotype. Mutational analysis revealed in the first patient the APC germline mutation 3183_87del ACAAA and in the second patient the del9-10 (del9080dup11) novel APC variant; the first mutation has been already reported in association with PTC; to our knowledge the second mutation has never been previously reported in association with FAP.

CONCLUSIONS

In the population examined, the estimated prevalence of thyroid malignant diseases was 3.7%. In both patients, the identified APC gene pathogenetic variants mapped within the 5' region of the gene, previously reported as a PTC-associated mutational hot spot. Both patients had classic FAP phenotype and genetic analysis revealed two pathogenetic APC mutations: c.3183_87delACAAA, a recurrent pathogenetic variant and del9-10 (del9080dup11), a novel, not previously described genomic rearrangement. In agreement with previous studies, the morpho-functional surveillance of thyroid in FAP series should be recommended. A better insight into the overall genotype-phenotype correlation of APC gene mutations would be helpful for the identification of at-risk individuals.

Gene variants associated to malignant thyroid disease in familial adenomatous polyposis: a novel APC germline mutation

BACKGROUND AND AIM

Familial adenomatous polyposis (FAP) is an autosomal inherited syndrome characterized by hundreds to thousands colorectal adenomatous polyps with oncological transformation lifetime risk of 100%. FAP is mainly associated with mutations in APC (autosomal dominant inheritance) or MUTYH (autosomal recessive inheritance) genes. Affected individuals are at increased risk of developing extra-intestinal tumors. Lifetime risk of developing thyroid carcinoma has been described in previous reports of about 2-12%, mainly in females, and the mean age is below 30 yr. About 95% of cancers are papillary thyroid carcinomas (PTC), mostly multifocal. The aim of this study was to evaluate the frequency of PTC among our series of FAP patients and to assess the type of gene mutation associated with the disease.

METHODS

Fifty-four subjects from 36 FAP families were selected (29 females/25 males) and the mean age (±SD) at diagnosis was 28.8±10.8 yr. All patients underwent blood examination for thyroid hormones and antibodies, germline mutational analysis of APC and/or MUTYH genes, thyroid ultrasound, and endocrinological evaluation.

RESULTS

In 13/54 (24.1%) subjects, an eumetabolic thyroid disease was found: plurinodular disease in 7/54 (13.0%); single nodule in 4/54 (7.4%); in 2/54 patients (3.7%), we found a malignant nodule characterized after total thyroidectomy as a classical PTC. Both patients were female and showed a classic FAP phenotype. Mutational analysis revealed in the first patient the APC germline mutation 3183_87del ACAAA and in the second patient the del9-10 (del9080dup11) novel APC variant; the first mutation has been already reported in association with PTC; to our knowledge the second mutation has never been previously reported in association with FAP.

CONCLUSIONS

In the population examined, the estimated prevalence of thyroid malignant diseases was 3.7%. In both patients, the identified APC gene pathogenetic variants mapped within the 5' region of the gene, previously reported as a PTC-associated mutational hot spot. Both patients had classic FAP phenotype and genetic analysis revealed two pathogenetic APC mutations: c.3183_87delACAAA, a recurrent pathogenetic variant and del9-10 (del9080dup11), a novel, not previously described genomic rearrangement. In agreement with previous studies, the morpho-functional surveillance of thyroid in FAP series should be recommended. A better insight into the overall genotype-phenotype correlation of APC gene mutations would be helpful for the identification of at-risk individuals.

Hyperthermic isolated perfusion with tumor necrosis factor-alpha and doxorubicin for the treatment of limb-threatening soft tissue sarcoma: the experience of the Italian Society of Integrated Locoregional Treatment in Oncology (SITILO)

BACKGROUND

Tumor necrosis factor-alpha (TNFalpha)-based hyperthermic isolated limb perfusion (HILP) is routinely carried out at most oncological institutions in the treatment of locally advanced soft tissue limb sarcoma (STS), employing high TNFalpha dosages. After a phase I-II study, the SITILO (Italian Society of Integrated Locoregional Therapies in Oncology) centers began to employ the lower dose of 1 mg of TNFalpha. The aim of this paper is to report on the results obtained in 75 patients with limb-threatening STS treated with a low TNFalpha dose and doxorubicin (Dx).

PATIENTS AND METHODS

HILP with TNFalpha (at a dosage of either <or=1 mg or >1 mg) and Dx was administered to 75 patients with limb-threatening STS: 37 males and 38 females; median age 50 years; tumor in the lower and upper limbs in 58 and 17 patients, respectively; primary and recurrent tumors in 45 and 30 patients, respectively. Most tumors (77%) were high grade. Tumor resection was carried out 6 to 8 weeks after HILP.

RESULTS

The grade of limb toxicity was mild to moderate in the vast majority of patients (76%). Grades IV and V were observed, but only when high muscle temperatures were recorded and high TNFalpha dosages were employed. Systemic toxicity was also mild to moderate and there were no postoperative deaths. Complete and partial tumor responses were 34% and 48%, respectively, with an overall response of 82% . Limb sparing surgery was carried out in 85.3% of patients. At a median follow-up of 28 months, 16 recurrences (21.3%) were recorded, with a 5-year locoregional disease-free survival of 63% . The 5-year disease-free survival and overall survival were 36.7% and 61.6%, respectively.

CONCLUSION

HILP with 1 mg of TNFalpha is an effective neoadjuvant therapy resulting in a high rate of limb sparing in limb-threatening STS, with acceptable local reactions and negligible systemic toxicity.

Prognostic factors influencing tumor response, locoregional control and survival, in melanoma patients with multiple limb in-transit metastases treated with TNFalpha-based isolated limb perfusion

BACKGROUND

In isolated limb perfusion (ILP) with tumor necrosis factor-alpha (TNFalpha) and interferon (IFN)-gamma, pioneered by Lienard and Lejenne in 1988, TNFalpha was empirically employed at a dosage (3-4 mg) ten times higher than the systemic maximum tolerable dose (MTD). We previously conducted a phase I/II study in 20 patients with in-transit melanoma metastases, using a combination of melphalan and TNFalpha at dosages ranging from 0.5 to 3.3 mg. The dose of 1 mg of TNFalpha was identified as optimal in terms of both efficacy and toxicity. The aim of the present study was to describe our experience with 113 stage IIIA/IIIAB melanoma patients treated with a TNFalpha-based ILP and identify prognostic factors for response, locoregional control and survival.

PATIENTS AND METHODS

Patients at stage IIIA-IIIAB (presence of in-transit metastases and/or regional node involvement) were considered eligible. The disease was bulky (>or=10 nodules<or=3 cm or fewer nodules with a diameter>3 cm) in 42.5% of the patients and unresectable in 33% . Forty patients were treated with a TNFalpha dosage of >1 mg and 73 with 1 mg. Patients with tumors in the upper and lower limbs were submitted to ILP via axillary and iliac vessels, respectively. TNFalpha was injected in the arterial line of an extracorporeal circuit at the pre-established dose, followed by melphalan (13 and 10 mg/l of limb volume for the upper and lower limbs, respectively) 30 minutes later.

RESULTS

Complete responses (CR) and partial responses (PR) were 63% and 24.5%, respectively, with an objective response (OR) of 87.5%. No change (NC) was observed in only 12.5% of the patients. Upon multivariate analysis, only bulky disease maintained its independent value for tumor response with an odds ratio of 4.07 and a p-value of 0.02. The 5-year locoregional disease-free survival was 42.7%. Upon multivariate analysis, the only prognostic factors were stage, age and bulky disease. The 5-year overall survival was 49%. Multivariate analysis showed that only sex, stage and CR maintained their independent values.

CONCLUSION

TNFalpha-based ILP was proven to be an effective treatment for melanoma patients with in-transit metastases. The TNFalpha dosage of 1 mg was as effective as 3-4 mg, with lower toxicity and cost. We propose that TNFalpha and melphalan-based ILP should be employed for bulky tumors or after failure of melphalan-based ILP.

Effect of cabergoline added to levodopa treatment on sleep-wake cycle in idiopathic Parkinson's disease: an open label 24-hour polysomnographic study

Few studies focused on the effects of cabergoline on sleep-wake cycle in PD. Twelve patients affected by PD treated with levodopa as monotherapy underwent two 24-hour ambulatory polysomnographic (A-PSG) sessions twice: in baseline condition (levodopa as monotherapy) and after addition of cabergoline. In each condition, a subjective evaluation of sleep quality and daytime sleepiness was obtained by means of Parkinson's disease Sleep Scale (PDSS) and the Epworth Sleepiness Scale. The statistical analysis of sleep parameters revealed a significant increase of sleep efficiency and slow wave sleep under cabergoline. The PDSS total score showed a significant improvement of overall sleep quality after cabergoline. No significant changes in daytime sleepiness were observed. No patient referred and/or showed sleep attacks before and after addition of cabergoline. We hypothesize that the long-lasting effect of cabergoline may improve the objective quality of nocturnal sleep in PD patients complaining nocturnal motor disability without inducing daytime sleepiness.

Expression of single-chain antibodies in transgenic plants

There is an ever-growing interest in plant molecular farming as a system for producing valuable recombinant pharmaceutical molecules, such as single-chain variable fragments, on an industrial/agricultural scale and it appears that it is going to become a reality. Human epidermal growth factor receptor-2 (HER2) is an oncogene involved in abnormal cell growth in breast cancer and is considered for the development of new cancer therapies. We describe here the cloning and expression of a scFv-alpha HER2 that has been produced in Escherichia coli and in plants using both stable and transient systems in tobacco and Nicotiana benthamiana. Single-chain antibodies (ScFvs) extracted and purified from E. coli and plant tissues were tested for functionality and specificity by flow cytometry analysis on several cell lines and showed positive results when used on breast cancer slides coming from human frozen tissues. As a result, scFv-alpha HER2 represents a good opportunity for application and use in diagnosis and therapy.

Temporal administration of entacapone with slow release L-dopa: pharmacokinetic profile and clinical outcome

Entacapone is a specific, peripherally acting catechol- O-methyltransferase (COMT) inhibitor that prevents peripheral degradation of L-dopa, thus improving its bioavailability. Entacapone is known to have pharmacokinetics similar to standard L-dopa but not to that of controlled-release (CR) L-dopa. The aim was to determine whether delayed entacapone administration may prolong CR L-dopa half-life in comparison to the co-administration modality. We compared plasma L-dopa concentrations after co-administration of CR L-dopa and entacapone or after administration of CR and a delayed (30 and 90 minutes) entacapone dose in 10 parkinsonian patients. The area under the concentration-time curve and other pharmacokinetic parameters were not changed by the delayed administration of entacapone. Different temporal modalities of entacapone administration had similar effects on CR L-dopa pharmacokinetics and on L-dopa-induced clinical improvement.

Deep brain stimulation (DBS) attentional effects parallel those of l-dopa treatment

Aim of our study was to investigate the different effects on attentional capacity of deep brain stimulation DBS (STN or GPi) and of l-dopa in PD patients. Patients were evaluated on-DBS/off-l-dopa, on-l-dopa/off-DBS, on-l-dopa/on-DBS and off-l-dopa/off-DBS. Our results indicate that DBS effects on attentional functions parallel those of l-dopa. A site independent (both STN and GPi) worsening of verbal fluency was observed, possibly connected to the stimulus effect on the cortico-subcortical-cortical loop.

Subdyskinetic apomorphine responses in globus pallidus and subthalamus of parkinsonian patients: lack of clear evidence for the 'indirect pathway'

OBJECTIVES

Previous studies suggested that the hypo-activity of the external pallidus (GPe) might drive the hyper-activity of subthalamic neurons, which underlies the cardinal symptoms of Parkinson's disease. We have challenged this view, based on the so-called 'indirect pathway', by recording apomorphine effects from both structures of parkinsonian patients, at rest and during passive movements.

METHODS

We performed single-unit recordings from external pallidus (GPe), internal pallidus (GPi) and subthalamic nucleus (STN) during the stereotactic neurosurgery aimed to implant deep brain stimulating electrodes in GPi or STN. First, we verified the firing frequency of each structure in off-state conditions. Then, therapeutic, subdyskinetic concentrations of the dopaminergic agonist apomorphine was delivered to assess each nucleus response.

RESULTS

The firing rate of STN averaged about 40 Hz; a large proportion (75%) of STN units exhibited marked responsiveness to passive movements. Apomorphine reduced the firing discharge of parkinsonian STN in all cells, although electrophysiological recovery was usually incomplete. Movement-related activity was also dramatically reduced. In contrast, apomorphine failed to modify the firing frequency of GPe, despite the amelioration of hypo-kinetic symptoms and the simultaneous inhibition of GPi firing discharge.

CONCLUSIONS

We demonstrate that part of the models on basal ganglia circuitry needs to be revised. The re-balancing of STN hyper-activity, when patients benefit from dopaminergic therapy, is not due to an increased input from GPe, but, instead, due to changes in STN intrinsic firing properties and/or modulation of glutamatergic inputs.

Deep brain stimulation of both subthalamic nucleus and internal globus pallidus restores intracortical inhibition in Parkinson's disease paralleling apomorphine effects: a paired magnetic stimulation study

OBJECTIVE

We investigated the effect of bilateral subthalamic nucleus (STN) and internal globus pallidus (GPi) deep brain stimulation (DBS) on intracortical inhibition (ICI) in patients with advanced Parkinson's disease (PD).

METHODS

The activity of intracortical inhibitory circuits was studied in 4 PD patients implanted with stimulating electrodes both in STN and GPi by means of paired-pulse transcranial magnetic stimulation, delivered in a conditioning-test design at short (1-6 ms) interstimulus intervals (ISI). The effect of apomorphine on the same PD patients was also investigated.

RESULTS

We observed that implanted PD patients showed a significant increase in ICI during either bilateral STN or GPi DBS at 3 ms ISI, and during bilateral STN DBS at 2 ms ISI in comparison to their off DBS condition. The same statistical improvement was observed during apomorphine infusion at 3 and 2 ms ISI. In each condition, the electrophysiological changes were associated with a significant clinical improvement as measured by the Unified Parkinson's Disease Rating Scale motor examination.

CONCLUSIONS

These results are consistent with the hypothesis that basal ganglia DBS can mimic the effects of pharmacological dopaminergic therapy on PD patients cortical activity. We propose that in PD patients, the basal ganglia DBS-induced improvement of ICI may be related to a recovery in modulation of thalamo-cortical motor pathway.

Effect of apomorphine on cortical inhibition in Parkinson's disease patients: a transcranial magnetic stimulation study

In this study, transcranial magnetic stimulation (TMS) of the primary motor hand area was used to test cortical excitability in Parkinson's disease (PD) patients. Motor evoked potentials (MEPs) to TMS were studied at rest by utilising distinct paired-pulse TMS protocols. Out of 29 untreated PD patients and 29 healthy subjects, early cortical inhibition (1-6 ms) was studied in a first subgroup of 17 PD patients and 15 healthy subjects, whereas late cortical inhibition (20-200 ms) was studied in a second subgroup of 21 PD patients and 19 healthy subjects. In all PD patients the same TMS protocols were performed before and after 3 h of apomorphine infusion. In comparison to healthy subjects, untreated PD patients showed a significant reduction of both early and late cortical inhibition, which was maximal at 2-3 ms, and at 80-100 ms, respectively. Apomorphine administration consistently reversed all the MEP abnormalities found in PD patients. The lack of TMS effects on the Hoffman's reflex (HR), at those intervals revealing the reduced inhibition in PD patients, is compatible with a supraspinal origin of the observed MEP abnormalities. Our data suggest that the cortical and/or subcortical loss of dopaminergic transmission in PD patients is associated with impaired motor cortical inhibitory mechanisms, as tested by a decreased early and late MEP inhibition.

Bilateral GPi DBS is useful to reduce abnormal involuntary movements in advanced Parkinson's disease patients, but its action is related to modality and site of stimulation

In Parkinson's disease (PD) patients, internal globus pallidus (GPi) stimulation has been reported to produce good effects on abnormal involuntary movements (AIM); less improvement has been observed in extrapyramidal symptoms. We assessed the effect of monopolar dorsal (uppermost), ventral (lowest) and bipolar (uppermost vs. lowest) bilateral globus pallidus stimulation by quadripolar electrode on extrapyramidal symptoms and AIM induced by a dose of apomorphine. Six PD patients were studied in OFF therapy condition after surgery without stimulation (STIM OFF) and during stimulation (STIM ON) with the three different modalities. All patients were evaluated by the unified Parkinson's disease rating scale, section III (UPDRS) and by the AIM. Our results show that all three bilateral GPi stimulation modalities reduce the UPDRS score (between 49.7 and 31.5%), although the bipolar and lowest stimulation are the most effective. Similarly, bipolar and lowest stimulation were also the most effective in reducing the occurrence and intensity of the apomorphine-induced AIM. On the contrary, uppermost stimulation (UP ON) produced an AIM occurrence similar to that observed in the OFF stimulus condition. We suggest that bilateral GPi stimulation is an useful procedure to ameliorate extrapyramidal signs of advanced PD patients; however, it produces an antidyskinetic effect only if the ventral or the entire GPi is stimulated. On the contrary, the UP ON, most probably located in the external globus pallidus (GPe), does not modify the AIM occurrence.

The activation of mu opioid receptors promotes a small modulation of calcium currents in rat pallidal neurons

Globus pallidus receives, from dorsal neostriatum, a dense enkephalinergic innervation whose role is still uncertain. We examined the possibility that the activation of mu, delta or k opioid receptors modulate high-voltage-activated calcium currents in isolated GP neurons. Neither dynorphin nor DPEPE inhibited calcium current, whilst DAMGO produced a small (-16%) but consistent response, selectively antagonized by CTOP. The mu-mediated modulation required the activation of G-proteins but was voltage-independent. The pre-incubation in omega-conotoxinVIA abolished the response, implying the involvement of N-type calcium channels. These findings suggest that enkephalin may exert a direct influence on GP excitability also through post-synaptic effects. In degenerative conditions as Parkinsonism, an excessive stimulation of mu binding sites might induce a pathological inhibition of calcium signals, thus contributing to modify the GP firing pattern and transmitter release.

Ionic mechanisms underlying differential vulnerability to ischemia in striatal neurons

Brain cells express extremely different sensitivity to ischemic insults. The reason for this differential vulnerability is still largely unknown. Here we discuss the ionic bases underlying the physiological responses to in vitro ischemia in two neostriatal neuronal subtypes exhibiting respectively high sensitivity and high resistance to energy deprivation. Vulnerable neostriatal neurons respond to ischemia with a membrane depolarization. This membrane depolarization mainly depends on the increased permeability to Na+ ions. In contrast, resistant neostriatal neurons respond to ischemia with a membrane hyperpolarization due to the opening of K+ channels. Interestingly, in both neuronal subtypes the ischemia-dependent membrane potential changes can be significantly enhanced or attenuated by a variety of pharmacological agents interfering with intracellular Ca2+ entry, ATP-dependent K+ channels opening, and Na+/Ca2+ exchanger functioning. The understanding of the ionic mechanisms underlying the differential membrane responses to ischemia represents the basis for the development of rational neuroprotective treatments during acute cerebrovascular insults.

Cerebrovascular reactivity and subcortical infarctions

OBJECTIVES

To investigate the association between different kinds of ischemic lesions and cerebrovascular reactivity (CR) and to evaluate their relationships with the major risk factors for stroke.

SUBJECTS AND METHODS

We evaluated CR using the breath-holding index technique during bilateral transcranial Doppler monitoring of flow velocity in the middle cerebral arteries of 41 consecutive patients attending our clinic for a recent, first-ever, ischemic stroke and in 15 control subjects. Based on the location of the lesion determined by computed tomography, the following 3 types of infarctions were identified: cortical (or territorial), single subcortical, and subcortical with multiple silent subcortical infarctions. Patients with a condition of severe carotid artery stenosis or occlusion, which in itself could account for altered CR, were excluded from this study. All physiological and pathologic conditions that could possibly cause an impairment in CR were recorded.

RESULTS

The breath-holding index was significantly lower in the multiple subcortical infarctions group than in the control subjects (P < .001), single subcortical infarctions group (P < .01), and cortical infarctions group (P < .01). In all of the groups male sex (P < .05) and a history of hypertension (P < .05), regardless of whether hypertension was treated, correlated with low CR. The multiple regression analysis indicated that the only significant factor able to influence the breath-holding index was the type of lesion.

CONCLUSIONS

Nonstenotic patients with first-ever stroke who had a recent symptomatic subcortical infarction associated with multiple silent infarctions seem to have an impaired cerebrovascular reserve capacity. The strong association of subcortical infarctions with multiple silent infarctions with low CR indicates the role of small vessel vasculopathy and hypoperfusion as possible pathogenetic mechanisms of subcortical infarctions with multiple silent infarctions.

Cerebral hemodynamics in patients with carotid artery occlusion and contralateral moderate or severe internal carotid artery stenosis

OBJECT

The purpose of this study was to evaluate cerebral hemodynamics in patients suffering from occlusion of the carotid artery (CA) and contralateral CA stenosis.

METHODS

Using transcranial Doppler ultrasonography, the cerebrovascular reactivity to hypercapnia in the middle cerebral arteries was evaluated by calculating the breath-holding index (BHI) of 69 symptomatic patients suffering from internal CA (ICA) occlusion and moderate or severe contralateral ICA stenosis. To evaluate which variables influenced BHIs ipsilateral to the site of ICA occlusion, a multiple stepwise linear regression analysis was performed that included the following factors: patient age, percentage of contralateral ICA stenosis, contralateral BHI, number of collateral pathways, and presence of hypertension, diabetes, smoking, and hyperlipidemia. An analysis of variance was conducted to evaluate the impact of the type of collateral vessels on the BHI. A regression analysis showed that the BHI ipsilateral to the site of ICA occlusion could be accounted for by the contralateral BHI (which was entered at the first step of the analysis, p < 0.001) and by the number of collateral pathways (which was entered at the second step, p = 0.033). Neither the degree of contralateral ICA stenosis nor the other variables could be added to improve the model. The analysis demonstrated that the absence of collateral pathways and the presence of the anterior communicating artery (ACoA) alone were associated with lower BHI values than those found in the presence of two or three collateral vessels, regardless of the presence of an anterior collateral pathway.

CONCLUSIONS

On the basis of these data one can infer that the cerebral hemodynamic status of patients with occlusive disease of the CA is influenced by individual anatomical and functional characteristics. Because improvement in contralateral hemodynamics after surgical correction of an ICA stenosis can only be expected in the presence of an ACoA, the planning of strategies for influencing cerebral blood flow distal to an ICA occlusion and, in particular, the consideration of a contralateral carotid endarterectomy, should be preceded by a careful evaluation of the intracranial hemodynamic adaptive status of the patient. Particular attention should be paid to cerebrovascular reactivity and the number and type of collateral vessels that are present.

Influence of physiologic oscillation of estrogens on cerebral hemodynamics

The interactions between estrogens and the cerebrovascular system are complex and not fully understood. There are evidences suggesting that the hormones confer protection against cerebral ischemia. Our aim in this study was to investigate the effects of physiological variations of estradiol plasmatic concentration on cerebral hemodynamics. We investigated cerebrovascular reactivity to hypercapnia with transcranial Doppler ultrasonography and the breath-holding index method in the right middle cerebral artery of 20 young women during the menstrual and the ovulatory phase. Data were compared with those of 20 men matched for age. The mean value of the breath-holding index was significantly higher (p<0.001) in females during the ovulatory phase than in the menstrual phase. In men, values were similar to those of women during the menstrual phase. These results suggest that estrogens influence the adaptation capacity of the cerebrovascular system. The possible pathophysiological implications of the relationships between sex hormones and cerebral hemodynamics deserve further investigation.

Intracellular localization and isoform expression of the voltage-dependent anion channel (VDAC) in normal and dystrophic skeletal muscle

Voltage-dependent anion channels (VDACs) are a family of pore-forming proteins encoded by different genes, with at least three protein products expressed in mammalian tissues. The major recognized functional role of VDACs is to permit the almost free permeability of the outer mitochondrial membrane (OMM). Although VDAC1 is the best known among VDAC isoforms, its exclusively mitochondrial location is still debated. Therefore, we have measured its co-localization with markers of cellular organelles or compartments in skeletal muscle fibers by single or double immunofluorescence and traditional as well as confocal microscopy. Our results show that VDAC1 immunoreactivity corresponds to mitochondria and sarcoplasmic reticulum, while sarcolemmal reactivity, previously reported, was not observed. Since VDAC1 has been suggested to be involved in the control of oxidative phosphorylation, we sought for possible gene regulation of VDAC1, VDAC2 and VDAC3 in skeletal muscle of the dystrophin-deficient mdx mouse, which suffers of an impaired control of energy metabolism. Our results show that, while VDAC1 mRNA and protein and VDAC2 mRNA are normally expressed. VDAC3 mRNA is markedly down-regulated in mdx mouse muscle at different ages (before, during and after the outburst of myofiber necrosis). This finding suggests a possible involvement of VDAC3 expression in the early pathogenic events of the mdx muscular dystrophy.

The effects of gabapentin on different ligand- and voltage-gated currents in isolated cortical neurons

A clear picture of the mechanisms of action of the anti-epileptic agent gabapentin is far from being accomplished. We have analyzed the effects of gabapentin on ligand- and voltage-gated currents in isolated adult rat cortical neurons. Gabapentin failed to modify glutamate currents and produced a slight reduction of GABA responses. Negligible inhibition of sodium, but consistent inhibition of high-voltage-activated calcium conductance was promoted by gabapentin. In addition, gabapentin reduced calcium current sensitivity to dihydropyridine agonist and antagonists. Interestingly, gabapentin also decreased a not-inactivating, cadmium-sensitive, potassium current. These unconventional effects might underlie its efficacy in a variety of diseases which involve periodic discharge patterns as neuropathic pain or essential tremor.

Hypoglycemia enhances ionotropic but reduces metabotropic glutamate responses in substantia nigra dopaminergic neurons

It is widely accepted that energy deprivation causes a neuronal death that is mainly determined by an increase in the extracellular level of glutamate. Consequently an excessive membrane depolarization and a rise in the intracellular concentration of sodium and calcium are produced. In spite of this scenario, the function of excitatory and inhibitory amino acids during an episode of energy failure has not been studied yet at a cellular level. In a model of cerebral hypoglycemia in the rat substantia nigra pars compacta, we measured neuronal responses to excitatory amino acid agonists. Under single-electrode voltage-clamp mode at -60 mV, the application of the ionotropic glutamate receptor agonists N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid, kainate, and the metabotropic group I agonist (S)-3,5-dihydroxyphenilglycine (DHPG) produced reversible inward currents in the dopaminergic cells. In addition, an outward current was caused by the superfusion of the metabotropic GABA(B) agonist baclofen. Glucose deprivation enhanced the inward responses caused by each ionotropic glutamate agonist. In contrast, hypoglycemia depressed the DHPG-induced inward current and the baclofen-induced outward current. These effects of hypoglycemia were reversible. To test whether a failure of the Na(+)/K(+) ATPase pump could account for the modification of the agonist-induced currents during hypoglycemia, we treated the midbrain slices with strophanthidin (1-3 microM). Strophanthidin enhanced the inward currents caused by glutamate agonists. However, it did not modify the GABA(B)-induced outward current. Our data suggest that glucose deprivation enhances the inward current caused by the stimulation of ionotropic glutamate receptors while it dampens the responses caused by the activation of metabotropic receptors. Thus a substantial component of the augmented neuronal response to glutamate, during energy deprivation, is very likely due to the failure of Na(+) and Ca(2+) extrusion and might ultimately favor excitotoxic processes in the dopaminergic cells.

Cell-type specificity of mGluR activation in striatal neuronal subtypes

The effects of metabotropic glutamate receptor (mGluR) activation were studied in medium spiny neurons and large aspiny (LA) interneurons by means of electrophysiological and optical recordings. DCG-IV and L-SOP, agonists for group II and III mGluRs, respectively, produced a presynaptic inhibitory effect on corticostriatal glutamatergic excitatory postsynaptic potentials (EPSPs) in both spiny and LA cells. Activation of group I mGluRs by the selective agonist 3,5-DHPG produced no effect on membrane properties and glutamatergic transmission in spiny neurons, whereas it did cause a membrane depolarization in LA interneurons coupled to increased input resistance. In combined optical and electrophysiological experiments, in spiny neurons 3,5-DHPG enhanced membrane depolarization and intracellular calcium (Ca2+) levels induced by NMDA applications, but not in LA interneurons. These data suggest the existence of a positive interaction between NMDA and group I mGlu receptors only in medium spiny cells which might, at least partially, account for the differential vulnerability to excitotoxic damage observed in striatal neuronal subtypes.

Nitrergic neurons make synapses on dual-input dendritic spines of neurons in the cerebral cortex and the striatum of the rat: implication for a postsynaptic action of nitric oxide

Pre-embedding electron microscopic immunocytochemistry was used to examine the ultrastructure of neurons containing nitric oxide synthase and to evaluate their synaptic relationships with target neurons in the striatum and sensorimotor cerebral cortex. Intense nitric oxide synthase immunoreactivity was found by light and electron microscopy in a type of aspiny neuron scattered in these two regions. The intensity of the labeling was uniform in the soma, dendrites and axon terminals of these neurons. In both forebrain regions, nitric oxide synthase-immunoreactive neurons received synaptic contacts from unlabeled terminals, which were mostly apposed to small-caliber dendrites. The unlabeled symmetric contacts were generally about four times as abundant as the unlabeled asymmetric contacts on the nitric oxide synthase-immunoreactive neurons. Terminals labeled for nitric oxide synthase were filled with synaptic vesicles and were observed to contact unlabeled neurons. Only 54% (in the cerebral cortex) and 44.3% (in the striatum) of the nitric oxide synthase-immunoreactive terminals making apposition with the target structures were observed to form synaptic membrane specializations within the plane of the randomly sampled sections. The most common targets of nitric oxide synthase-immunoreactive terminals were thin dendritic shafts (54% of the immunoreactive terminals in the cortex and 75.7% of the immunoreactive terminals in the striatum), while dendritic spines were a common secondary target (42% of the immunoreactive terminals in the cortex and 20.6% of the immunoreactive terminals in the striatum). The spines contacted by nitric oxide synthase-immunoreactive terminals typically also received an asymmetric synaptic contact from an unlabeled axon terminal. These findings suggest that: (i) nitric oxide synthase-immunoreactive neurons in the cortex and striatum preponderantly receive inhibitory input; (ii) nitric oxide synthase-containing terminals commonly make synaptic contact with target structures in the cortex and striatum; (iii) spines targeted by nitric oxide synthase-containing terminals in the cortex and striatum commonly receive an asymmetric contact as well, which may provide a basis for a synaptic interaction of nitric oxide with excitatory input to individual spines.

Stimulation of nitric oxide-cGMP pathway excites striatal cholinergic interneurons via protein kinase G activation

Conflicting data have been collected so far on the action of nitric oxide (NO) on cholinergic interneurons of the striatum. In the present in vitro electrophysiological study, we reported that intracellularly recorded striatal cholinergic interneurons are excited by both hydroxylamine and S-nitroso-N-acetylpenicillamine, two NO donors. This excitation persisted unchanged in the presence of glutamate, dopamine, and substance P receptor antagonists as well as after blockade of tetrodotoxin (TTX)- and calcium channel-sensitive transmitter release, suggesting that NO produces its effects by modulating directly resting ion conductances in the somatodendritic region of striatal cholinergic cells. The depolarizing effect of hydroxylamine was greatly reduced by lowering external concentrations of sodium ions (from 126 to 38 mm) and did not reverse polarity in the voltage range from -120 to -40 mV. The sodium transporter blockers bepridil and 3',4'-dichlorobenzamil were conversely ineffective in preventing NO-induced membrane depolarization. Intracellular cGMP elevation is required for the action of hydroxylamine on striatal cholinergic cells, as demonstrated by the findings that the membrane depolarization produced by this pharmacological agent was prevented by bath and intracellular application of two inhibitors of soluble guanylyl cyclase and was mimicked and occluded by zaprinast, a cGMP phosphodiesterase inhibitor. Finally, intracellular Rp-8-Br-cGMPS, a protein kinase G (PKG) inhibitor, blocked the hydroxylamine-induced membrane depolarization of cholinergic interneurons, whereas both okadaic acid and calyculin A, two protein phosphatase inhibitors, enhanced it, indicating that intracellular PKG and phosphatases oppositely regulate the sensitivity of striatal cholinergic interneurons to NO. The characterization of the cellular mechanisms involved in the regulation of striatal interneuron activity is a key step for the understanding of the role of these cells in striatal microcircuitry.

Reduced L-dopa absorption and increased clinical fluctuations in Helicobacter pylori-infected Parkinson's disease patients

We report that the area under the curve of L-dopa plasma concentration, following the administration of a single 250 mg L-dopa dose, is augmented after Helicobacter pylori (HP) eradication in six Parkinson's disease (PD) patients showing high IgG antibody titer against HP. A prolongation of L-dopa clinical benefit was also observed. We suggest that HP infection-activated gastric alterations may be responsible, at least in part, for the reported erratic efficacy of oral L-dopa therapy in some advanced PD patients. Given the high percentage of HP-positivity in the age cohorts including the largest prevalence of PD patients, we propose that HP eradication be recommended in all PD patients under L-dopa therapy.

Microdialysis in Parkinsonian patient basal ganglia: acute apomorphine-induced clinical and electrophysiological effects not paralleled by changes in the release of neuroactive amino acids

During stereotaxic neurosurgery for deep brain stimulation in Parkinson's disease (PD), we performed a microdialysis study of the extracellular amino acid (aspartate, glutamate, glycine, and GABA) concentrations. Their levels were measured in the GPe/GPi of five and in the STN of four different PD patients, after prolonged therapy washout. The results show stable values of basal release of the examined amino acids within 1 h. The basal levels of GABA in "OFF" state were significantly higher in the GPi than in the GPe. Acute apomorphine administration, while inducing clinical amelioration and electrophysiological changes in the examined nuclei, did not change amino acid concentrations. This result could be related to a limited microdialysis ability to detect subtle changes in amino acid spontaneous release. Alternatively, it could suggest that dopaminergic receptors located in the output nuclei, possibly present also in humans, might mediate the acute apomorphine clinical effects, not involving amino acid changes along the direct and/or indirect pathway.

An abnormal striatal synaptic plasticity may account for the selective neuronal vulnerability in Huntington's disease

A marked decrease in the activity of mitochondrial complex II (succinate dehydrogenase, SD) has been found in the brains of Huntington's disease (HD) patients. Here we have examined the possibility that SD inhibitors might produce their toxic action by increasing corticostriatal glutamatergic transmission. We report that SD inhibitors produce a durable augmentation of NMDA-mediated corticostriatal excitation (DANCE) in striatal spiny neurons, but not in striatal cholinergic interneurons. DANCE involves increased intracellular calcium, activation of MAP kinase ERK and is critically dependent upon endogenous dopamine (DA) acting via D2-like receptors. This pathological form of corticostriatal synaptic plasticity might play a key role in the regional and cell-type specific neuronal death observed in HD.

Clinical and electrophysiological effects of apomorphine in Parkinson's disease patients are not paralleled by amino acid release changes: a microdialysis study

We performed a microdialysis investigation of extracellular amino acid (glutamate and GABA) concentrations during sterotaxic neurosurgery (the implantation of permanent electrodes in the internal globus pallidus (GPi) or subthalamic nucleus (STN) for deep brain stimulation in advanced Parkinson's disease (PD) patients, after prolonged therapy wash-out). Electrophysiological single unit recordings and perioperative clinical status assessments were also performed. Amino acid levels were measured in the GPi and GPe (external globus pallidus) of three PD patients and in the STN of another three PD patients. Stable basal release values of the examined amino acids were obtained within one hour. In clinical "off" state, the basal levels of GABA in the GPi were double those in the GPe in all the three patients. This finding could represent a biochemical marker for GPi target identification in PD surgery. Acute subcutaneous apomorphine administration induced electrophysiological changes and clinical amelioration but did not change amino acid concentrations. This result could be due to methodological limitations of the microdialysis technique. Alternatively, it could suggest that the clinical effects of acute apomorphine might also be mediated by direct activation of dopaminergic receptors located in the output nuclei.

Role of tonically-active neurons in the control of striatal function: cellular mechanisms and behavioral correlates

1. The striatum is primarily involved in motor planning and motor learning. Human diseases involving its complex circuitry lead to movement disorders such as Parkinson's disease (PD) and Huntington's disease (HD). Moreover the striatum has been involved in processes linked to reward, cognition and drug addiction. 2. The high content of acetylcholine (ACh) found in the striatum is due to the presence of cholinergic interneurons. The intrinsic electrical and synaptic properties of these interneurons have been recently characterized. However, their functional significance is far from being fully elucidated. 3. In vivo electrophysiological experiments from behaving monkeys have identified these cholinergic interneurons as "Tonically Active Neurons" (TANs). They are activated by presentation of sensory stimuli of behavioral significance or linked to reward. 4. Experimental evidence showed that integrity of the nigrostriatal dopaminergic system is essential for TANs to express learned activity. 5. PD is known to be due to the loss of the nigrostriatal dopaminergic pathway and the ensuing imbalance between the content of dopamine and acetylcholine in the striatum. This evidence supports the hypothesis that cholinergic interneurons, or TANs, play a key role in the modulation of striatal function.

Selective vulnerability of pallidal neurons in the early phases of manganese intoxication

Prolonged exposure to manganese in mammals may cause an extrapyramidal disorder characterized by dystonia and rigidity. Gliosis in the pallidal segments underlies the well-established phase of the intoxication. The early phase of the intoxication may be characterized by psychic, nonmotor signs, and its morphological and electrophysiological correlates are less defined. In a rat model of manganese intoxication (20 mg/ml in drinking water for 3 months), neither neuronal loss nor gliosis was detected in globus pallidus (GP). However, a striking vulnerability of manganese-treated GP neurons emerged. The majority of GP neurons isolated from manganese-treated rats died following brief incubation in standard dissociation media. In addition, patch-clamp recordings in the whole-cell configuration were not tolerated by surviving GP neurons. Neither coeval but untreated GP neurons nor striatal ones manifested analogous susceptibility. Using the perforated-patch mode of recording we attempted at identifying the functional hallmarks of GP vulnerability: in particular, voltage-gated calcium currents and glutamate-induced currents were examined. Manganese-treated GP neurons exhibited calcium currents similar to control cells aside from a slight reduction in the dihydropyridine-sensitive current facilitation. Strikingly, manganese-treated GP cells--but not striatal ones--manifested peculiar responses to glutamate, since repeated applications of the excitatory amino acid, at concentrations which commonly promote desensitizing responses, produced instead an irreversible cell damage. Possible mechanisms are discussed.

HLA-G, -E, -F preworkshop: tools and protocols for analysis of non-classical class I genes transcription and protein expression

Non-classical MHC class I HLA-E, -F, and -G molecules differ from classical class I histocompatibility antigens by specific patterns of transcription, protein expression, and immunological functions. Restriction of the expression pattern of these non-classical antigens may play a key role in modulation of immune responses during pregnancy and diseases but remains to be additionally defined. A specific component of the second International Conference on HLA-G and the 13th HLA-G Histocompatibility Workshop will be dedicated to the analysis of transcription and expression of non-classical class I genes in normal and pathological tissues. In a first step, referred to as the preworkshop, we here report the analysis and conclusions of a working group which was constituted to gather and validate optimal reagents and protocols allowing RT-PCR analysis of HLA-E, -F, -G transcript levels and flow cytometry and immunochemistry analysis of HLA-G expression in cells and tissues. As a result of this work, use of specific primers and probes detecting alternative transcripts of HLA-E, -F, and G have been validated in transfected cells expressing differential pattern of HLA class I antigens. Analysis of the specificity and affinity of collected antibodies has allowed definition of reagents to be proposed for immunochemistry and flow cytometry analysis of HLA-G expression in normal and pathological tissues during the workshop. This work has allowed constitution of an extended workshop group which is now initiating analysis of non-classical class I transcription and expression in various cells and tissues, a collective contribution that will additionally refine our view of the expression of these antigens in normal and pathological situations.

Ipsilateral activation of the unaffected motor cortex in patients with hemiparetic stroke

BACKGROUND AND PURPOSE

Recent research has shown that following stroke patients can display ipsilateral activity reflecting a functional link between the undamaged hemisphere and the affected upper limb on the same side of the body. In the present study the capacity for ipsilateral activation is documented during recovery by using transcranial magnetic stimulation (TMS) and transcranial Doppler (TCD).

METHODS

Fourteen patients affected by hemispheric stroke were examined with TMS and TCD within 48 h of onset, and again 6 months later. Neurological signs were scored with reference to the NIHSS, and patients executed a thumb to finger opposition task so as to further estimate the motor deficit. Twenty healthy volunteers represented the control population.

RESULTS

(1) Both TMS and TCD yielded homogeneous results showing ipsilateral activity between affected hands and undamaged hemispheres. On stimulating the motor cortex 3 cm anterior and 3 cm lateral to Cz, a scalp site remote from the primary motor area, ipsilateral motor evoked potentials (iMEPs) from hand muscles were found in recovered patients. (2) In 8 controls iMEPs with smaller amplitudes than patients could be obtained by stimulating only the left hemisphere. (3) TCD revealed increased blood flow velocity in the ipsilateral MCA by activating the recovering hand (10.5+/-3.3%; P<0.001).

CONCLUSION

TMS reveals a specific area in the motor cortex from which ipsilateral MEPs can be elicited and both TMS and TCD indicate that an ipsilateral corticospinal tract can be accessible in some adult controls or becomes unmasked after cerebral damage.

Characterization of a major histocompatibility complex class II X-box-binding protein enhancing tat-induced transcription directed by the human immunodeficiency virus type 1 long terminal repeat

The X-box element present within the promoter region of genes belonging to the major histocompatibility complex (MHC) plays a pivotal role in the expression of class II molecules, since it contains the binding sites for several well-characterized transcription factors. We have analyzed a randomly selected compilation of viral genomes for the presence of elements homologous to the X box of the HLA-DRA gene. We found that human immunodeficiency virus type 1 (HIV-1) shows the highest frequency of X-like box elements per 1,000 bases of genome. Within the HIV-1 genome, we found an X-like motif in the TAR region of the HIV-1 long terminal repeat (LTR), a regulative region playing a pivotal role in Tat-induced HIV-1 transcription. The use of a decoy approach for nuclear proteins binding to this element, namely, XMAS (X-like motif activator sequence), performed by transfection of multiple copies of this sequence into cells carrying an integrated LTR-chloramphenicol acetyltransferase construct, suggests that this element binds to nuclear proteins that enhance Tat-induced transcription. In this report we have characterized two proteins, one binding to the XMAS motif and the other to the flanking regions of XMAS. Mobility shift assays performed on crude nuclear extracts or enriched fractions suggest that similar proteins bind to XMAS from HIV-1 and the X box of the HLA-DRA gene. Furthermore, a UV cross-linking assay suggests that one protein of 47 kDa, termed FAX (factor associated with XMAS)-1, binds to the XMAS of HIV-1. The other protein of 56 kDa was termed FAX-2. In a decoy ex vivo experiment, it was found that sequences recognizing both proteins are required to inhibit Tat-induced HIV-1 LTR-driven transcription. Taken together, the data reported in this paper suggest that XMAS and nearby sequences modulate Tat-induced HIV-1 transcription by binding to the X-box-binding proteins FAX-1 and FAX-2. The sequence homology between XMAS and X box is reflected in binding of a common protein, FAX-1, and similar functional roles in gene expression. To our knowledge, this is the first report showing that transcription factors binding to the X box of the MHC class II genes enhance the transcription of HIV-1.