MODULATION OF ALCOHOL PREFERENCE BY NMDA ANTAGONISTS IN MALE RATS

Chronic alcoholization by alcohol inhalation was used to studythe properties of magnesium, a non-competitive NMDA receptorantagonist, and CGP 39551, a competitive NMDA receptor antagonist,on behavioural dependence as estimated by the free-choice paradigm[alcohol 10% (v/v) vs. water], on the hypermotility after alcoholwithdrawal, and finally on the cortical vascularization. Thefirst experimental group received the drugs per os during thewhole alcoholization period. Magnesium (20 mg/kg/day) decreasedthe alcohol dependence while CGP 39551 (5 and 10 mg/kg/day)increased, in a dose-dependent manner, the dependence to alcohol.A second group of animals received the same drugs at the samedosages, not simultaneously during chronic alcoholization, butimmediately after alcoholization in one shot i.p. injection.In this case, rats receiving 5 mg/kg CGP 39551 never showedany dependence towards alcohol, while 10 mg/kg CGP 39551 or20 mg/kg magnesium prolonged the number of days of alcohol dependence.These results thus indicate the close interaction between NMDAreceptor function and dependence for alcohol. Magnesium hadno effects on hypermotility, while CGP 39551-treated animalspresented a decrease in the hypermotility observed after alcoholwithdrawal. Neither drug affected the hypervasculanzation accompanyingthe chronic alcoholization.     

PARENTAL HISTORY OF ALCOHOLISM: A RISK FACTOR FOR ALCOHOL-RELATED PERIPHERAL NEUROPATHIES

The aim of this study was to identify the risk factors of alcohol-relatedperipheral neuropathies. A case-control study was performedto compare two groups of alcoholic patients, one with peripheralneuropathy and the other without, but with alcohol-related cirrhosis,pancreatitis or cardiomyopathy. Ninety patients were recruitedin four in-patient units of a French hospital: 32 patients hada peripheral neuropathy and 58 patients did not. Univariateanalysis showed no differences between the two groups for sex,age, body mass index and duration of the alcoholic disease.Peripheral neuropathies were associated with a higher frequencyof parental history of alcoholism, severity of alcohol dependence,heavier alcohol consumption and more alcohol-related somaticdiseases. Multivariate analysis showed a strong relationshipbetween a parental history of alcoholism and the presence ofa neuropathy, when the severity of the alcoholic disease wastaken into account (adjusted OR = 6.8, IC_95% [2.2-21.6], P <0.001). The hypothesis that neuropathy may be a marker of aninherited susceptibility to alcoholism is discussed.     

SUPERFICIAL BLADDER TUMORS AND INCREASED REACTIVITY AGAINST MYCOBACTERIAL ANTIGENS BEFORE BACILLUS CALMETTE-GUERIN THERAPY

Purpose

The precise mechanism of action of bacillus Calmette-Guerin (BCG) in bladder cancer treatment remains poorly understood. Whether bladder tumor cells are destroyed by nonspecific mechanisms or targeted by specifically activated lymphocytes recognizing cognate antigens is unclear. To investigate a possible cross-reactivity between BCG and bladder cell tumors, we tested before BCG treatment the lymphoproliferation of peripheral blood lymphocytes against several mycobacterial antigens, including the secreted fibronectin binding antigen 85 complex from BCG (AG 85) in patients with superficial bladder tumors compared to control matched patients.

Materials and Methods

Using a whole blood assay, T cell response against purified protein derivative, BCG extract, whole BCG, purified AG 85, and the nonspecific mitogens pokeweed and phytohemagglutinin was investigated in 79 patients with superficial bladder tumors before BCG and in 39 control subjects without malignancy matched for age and sex. Neither group had a history of tuberculosis. Lymphoproliferation was measured with a tritiated thymidine uptake assay on day 7 of culture.

Results

Of the 79 patients with superficial transitional cell carcinoma, a significant lymphoproliferative response before BCG against PPD, BCG extract, whole BCG and AG 85 was observed in 65 (82.2%), 67 (84.81%), 30 (37.97%) and 49 (62.02%) patients, respectively. Of the 39 controls only 26 (64.1%), 23 (58.9%), 3 (7.7%) and 3 (7.7%) patients, respectively, had a significant lymphoproliferation against PPD, BCG extract, BCG and AG 85 (p >0.05, p = 0.004, p = 0.00001 and p = 0.00001, respectively). In terms of lymphoproliferative levels, patients with superficial transitional cell carcinoma also showed a significantly higher response against PPD (p = 0.000012), BCG extract (p = 0.000001), AG 85 (p = 0.000001), whole BCG (p = 0.00001) and pokeweed (p = 0.01) than controls but not against phytohemagglutinin.

Conclusions

Patients with superficial transitional cell carcinoma demonstrate an increased lymphoproliferation against mycobacterial antigens before BCG compared to control subjects. Although a nonspecific activation of the immune system cannot be excluded at this stage, our data may suggest the possible existence of bladder cancer antigens cross-reactive with mycobacterial antigens responsible for boosting precursor cells witnessing previous contacts with mycobacteria. The implication of these findings in the antitumoral mechanism of action of BCG are under investigation.     

Cerebrospinal fluid neopterin in paediatric neurology: a marker of active central nervous system inflammation

Aim  Cerebrospinal fluid (CSF) neopterin production is increased by interferon-gamma stimulation and appears to act as a marker of intrathecal immune activation. We aimed to test the usefulness of elevated CSF neopterin as a biological marker of central nervous system (CNS) inflammation.
Method  We retrospectively reviewed CSF neopterin in 158 children (89 males, 69 females, mean age 4y 1mo, SD 3y 11mo, range 1mo–15y).
Results  CSF neopterin levels in children with chronic static CNS disorders ( n =105) were predominantly low, suggesting that inflammation is rare in these patients. We created an upper value of normal (chronic static group 95th centile 27.4nmol/l). CSF neopterin was elevated in all 10 patients with acute encephalitis and in 10 of 12 patients with other acute inflammatory CNS disorders (demyelination, post-infectious ataxia, myelitis). CSF neopterin was also significantly elevated in patients with chronic progressive disorders of inflammatory origin. Interestingly, CSF neopterin was elevated in four of six patients with chronic static disorders who were tested during a febrile exacerbation of seizures or dystonia, suggesting that intrathecal immune activation may be important in this setting.
Interpretation  Neopterin has a short half-life and was useful for monitoring inflammation activity in a patient with relapsing–remitting encephalitis. CSF neopterin is a useful marker of inflammation in a broad range of acute and chronic CNS disorders, and is a significantly more sensitive marker of inflammation than CSF pleocytosis.     

Clinical association of intrathecal and mirrored oligoclonal bands in paediatric neurology

Aim Biomarkers such as autoantibodies, neopterin, and oligoclonal bands (OCBs) are increasingly used for the diagnosis of treatable inflammatory central nervous system (CNS) disorders. We investigated the correlation between the results of OCB testing and clinical diagnoses in a large contemporary cohort of children with a broad range of neurological conditions. Method Cerebrospinal fluid (CSF) and serum from 200 children (94 females, 106 males; age range 2mo–15y 10mo, mean age 6y 9mo, SD ±4.9) who underwent CSF investigation for their neurological condition were tested for OCBs using isoelectric focusing. Results The patients were divided into those with inflammatory (n=58) and non‐inflammatory (n=142) CNS disorders. Intrathecal OCBs (OCBs restricted to the CSF) were found in 11 out of 58 (19%) of those with inflammatory CNS disorders compared with none of the 142 patients with non‐inflammatory CNS disorders (p<0.001). Diseases associated with intrathecal OCB were multiple sclerosis, Rasmussen encephalitis, N‐methyl‐d ‐aspartate receptor (NMDAR) encephalitis, voltage‐gated potassium channel (VGKC) encephalopathy, herpes (HSV) encephalitis, ‘other’ encephalitides, acute cerebellar ataxia, and aseptic meningitis. Mirrored OCBs (identical OCBs in the serum and CSF) were less specific but were still found in 14 out of 58 (24%) children with inflammatory CNS disorders compared with only 6 out of 142 (4%) children with non‐inflammatory CNS disorders (p<0.001). Diseases associated with mirrored OCBs included acute disseminated encephalomyelitis (ADEM), VGKC encephalopathy, West syndrome, NMDAR encephalitis, ‘other’ encephalitides, polio‐like illness, Rasmussen encephalitis, cerebral vasculitis, metachromatic leukodystrophy, and bacterial meningitis. Intrathecal OCBs and mirrored OCBs had a positive predictive value for inflammatory CNS disease of 1 (95% confidence interval [CI] 0.68–1) and 0.7 (95% CI 0.46–0.87) respectively. Conclusion Intrathecal OCBs were restricted to patients with inflammatory CNS disorders. They are a useful, but non‐specific, biomarker of CNS inflammation of multiple causes. Mirrored OCBs are less specific, but still support a possible inflammatory CNS disorder. The presence of either intrathecal or mirrored OCBs should raise suspicion of an inflammatory CNS disorder.     

Cerebrospinal fluid CD19+ B‐cell expansion in N‐methyl‐D‐aspartate receptor encephalitis

There is increasing interest in the role of autoantibodies in acquired autoimmune central nervous system disorders. N‐methyl‐d ‐aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis defined by the presence of autoantibodies that bind to the NMDAR. Although there is evidence of NMDAR antibody pathogenicity, it is unclear which treatment results in the best outcome. We measured the proportion of B‐cells in the cerebrospinal fluid of two children with NMDAR encephalitis (a 6‐year‐old male and a 4‐year‐old female), one in the acute phase and one in the relapsing phase. The proportion of CD19⁺ B‐cells in both children was greater than 10%, significantly higher than seen in non‐inflammatory neurological disorders (<1%). This finding supports the use of drugs, such as rituximab, that deplete B‐cells in severe or refractory cases of NMDAR encephalitis, and lends further support to the humoral autoimmune hypothesis in NMDAR encephalitis.     

Setting in motion the immune mechanisms underlying genetically determined resistance and susceptibility to infection with Leishmania major

The murine model of infection with Leishmania major has allowed the demonstration of a causal relationship between, on the one hand, genetically determined resistance to infection and the development of a Th1 CD4⁺ cell response, and on the other hand, genetically determined susceptibility and Th2 cell maturation. Using this murine model of infection, the role of cytokines in directing the functional differentiation pathway of CD4⁺ T cell precursors, has been demonstrated in vivo . Thus, IL-12 and IFN-γ have been shown to favour Th1 cell development and IL-4 is crucial for the differentiation of Th2 responses. Maturation of a Th2 response in susceptible BALB/c mice following infection with L. major is triggered by the IL-4 produced during the first two days after parasite inoculation. This IL-4 rapidly renders parasite specific CD4⁺ T cells precursors unresponsive to IL-12. A restricted population of CD4⁺ T cells expressing the Vβ4Vα8 TCR heterodimer and recognizing a single epitope on the LACK (Leishmania Activated C-Kinase) antigen of L. major is responsible for this rapid production of IL-4, instructing subsequent differentiation towards the Th2 phenotype of CD4⁺ T cells specific for several parasite antigens .     

Influence of acute sleep loss on the neural correlates of alerting,orientating and executive attention components

The Attention Network Test (ANT) is deemed to assess the alerting, orientating and executive components of human attention. Capitalizing on the opportunity to investigate three facets of attention in a single task, we used functional magnetic resonance imaging (fMRI) to assess the effect of sleep deprivation (SD) on brain responses associated with the three attentional components elicited by the ANT. Twelve healthy volunteers were scanned in two conditions 1 week apart, after a normal night of sleep (rested wakefulness, RW) or after one night of total sleep deprivation. Sleep deprivation was associated with a global increase in reaction times, which did not affect specifically any of the three attention effects. Brain responses associated with the alerting effect did not differ between RW and SD. Higher‐order attention components (orientating and conflict effects) were associated with significantly larger thalamic responses during SD than during RW. These results suggest that SD influences different components of human attention non‐selectively, through mechanisms that might either affect centrencephalic structures maintaining vigilance or ubiquitously perturb neuronal function. Compensatory responses can counter these effects transiently by recruiting thalamic responses, thereby supporting thalamocortical function.