Jørgen Clausen

MYELIN CONSTITUENTS OF HUMAN CENTRAL NERVOUS SYSTEM

Recently, accounts have been presented of the complete quantitativc distribution of membrane constituents in grey matter, white matter, and in myelin and other subcellular particulate fractions of the central nervous system (CNS) (survey by Mokrasch 1969, Rouser & Yarriainoto 1969, Clausen 1969). Data from these studies have made possible a morc detailed elucidation of the changes of CNS under pathological conditions. e.g. multiple sclerosis (MS) . Although it has been shown that chemical changes related to the plaque formation characteristic of hlS involve disappearance of myelin constituents, deposits of cholesterol esters (survey by McAlpine, Lumsden & Acheson 1965) and increase in enzymic activities of zones surrounding the plaques (Friede 1966), the pathogenesis of MS is still obscure. In order to avoid the difficulties of exploring pathogenesis on the basis of studies of plaques with a population of cells differing from that of the original tissue (Greenfield et al. 1960), studies of MS in recent years have been concerned with the so-called normal white matter from MS patients. Such studies, based upon a rather small number of autopsy specimens, have revealed inconsistent changes in the composition of myelin, or of whole white matter. In a study of myelin from 3 cases of MS, Cumings & Goodwin ( 1968) demonstrated a decrease in the cerebroside/sulfatide ratio, and Gerstl et al. (1965) showed that M S myelin from 2 M S patients contained less cerebroside than normal myelin. The slight increase in fatty acid saturation found in the so-called “normal” MS white matter and myelin from MS patients (Cumings, Shortman & Skrbic 1966, Gerstl et al. 1965, Thompson 1966) may be related either to dietary, infectious or anoxic factors (vide infra) or to changes in the polar lipid and cholesterol composition, since the fatty acid profiles of phosphoand glycolipids differ (survey by Clausen 1969).

Biochemical and clinical effects of an antioxidative supplementation of geriatric patients. A double blind study.

Ninety seven geriatric patients from two Danish homes for old people accepted to participate in a blinded experiment designed to counteract ageing phenomena. The subjects were split into two groups, i.e., the verum and the placebo group. The verum group received daily for one year an antioxidative cocktail consisting of: 300 μg selenium asl-selenomethionine, 45 mg zinc, 270 mg vitamin C, 2.7 mg vitamin A, 6 mg vitamin B-6, and 465 mg vitamin E (d-alfatocopherol). Furthermore, in order to enhance exchange in polyenoic acids, each subject received daily 250 mg gamma-linolenic acid. The placebo groups received similar looking pills and capsules without the active components.During one year in the verum group, the whole blood selenium, the hydrogen-dependent glutathione peroxidase (GSH-Px) of erythrocytes, and the vitamin E level in serum was found increased compared to the pretreatment values and to the placebo group. No change could be traced in thet-butylhydroperoxide dependent GSH-Px, an enzyme that also assays the glutathione-s-transferase. During the same period of time, the fasting levels of serum fatty acid and the content of lipofuscin in erythrocytes were estimated. Compared to the pretreatment values, the lipofuscin level declined significantly and the level of w-3 penta- and hexaenoic acids increased in the verum, but not in the placebo group.During the study period, slight, but significant improvements in psychological scores could be traced. Furthermore, the assays of bloodflow in different areas of the brain surface (i.e., the ISI values) revealed a general trend to improvement in all areas, when the ISI values were compared during treatment with the pretreatment values and the values in the placebo group.

ERYTHROCYTE GLUTATHIONE PEROXIDASE DEFICIENCY IN MULTIPLE SCLEROSIS

The present study demonstrates a significant decrease in glutathione peroxidase activity in erythrocytes of 24 patients with multiple sclerosis (MS) when the data are expressed as enzymic units per mg hemoglobin and compared to data from normal controls without known family history of demyelinating diseases. Since selenium is an essential part of glutathione peroxidase, this study also compares the topographic differences in selenium availability (expressed as selenium content of forage) with the prevalence and death rates of MS in the USA. The comparison cannot exclude the possibility of a relationship between low selenium content and high prevalence of MS. The data are discussed in relationship to current theories on the pathogenesis of MS.

Demential syndromes and the lipid metabolism

Abstract– The present communication surveys the present knowledge about the extent to which formation of free radicals in the central nervous system may give rise to cross‐linking reactions finally ending in the deposition of lipofuscin pigments.

Leucocyte glutathione peroxidase activity and selenium level in multiple sclerosis

In continuation of our previous studies, which demonstrated a decreased glutathione peroxidase (GSH-Px) activity of erythrocytes from multiple sclerosis (MS) patients the activity of some enzymes regulating the peroxide level (GSH-PX and glutathione reductase (GSSG-Rd)) in leucocytes and erythrocytes respectively, the selenium level of whole blood and the beta-glucuronidase activity of serum (marker of lysosomal membrane damage) were assayed in this group of patients. GSH-Px activity in lymphocytes and granulocytes from MS patients was significantly (2 alpha smaller than or equal to 0.01) decreased by 35-50%. Erythrocyte glutathione reductase activity was only insignificantly decreased in MS patients. Erythrocyte GSH-Px : GSSG-Rd ratio was 11.0 for the control group, but 8.0 for the MS group. The selenium content of whole blood and serum from Danish MS patients was normal. The selenium level in erythrocytes from Danish MS patients was however higher than the selenium level in erythrocytes from controls.

Do endogenous retroviruses have etiological implications in inflammatory and degenerative nervous system diseases

Vertebrates carry large numbers of endogenous retroviruses (ERVs) and related sequences in their genomes. These retroviral elements are inherited as Mendelian traits. Generally, ERVs are defective without the ability of being expressed as viral particles. However, ERV sequences often have a potential for expression of at least some proteins. So far, the possible biological significance of ERVs is not clear. Nonetheless, there are observations suggesting a connection between ERVs and various diseases. This is the case with murine lupus and a spinal cord disease of certain mouse strains. In the present review, we discuss possible mechanisms by which ERVs could contribute to the development of human degenerative and inflammatory nervous system diseases, including direct effects on nervous system cells and immune cells. Interactions between ERVs and infectious viruses are also discussed. Finally, we review a possible retroviral etiology of multiple sclerosis.

CTLA4 in multiple sclerosis. Lack of genetic association in a European Caucasian population but evidence of interaction with HLA-DR2 among Shanghai Chinese.

In the present study we searched for an association between multiple sclerosis (MS) and the gene encoding the cytotoxic T lymphocyte antigen 4 (CTLA4). Our experimental approach involved amplification of DNA fragments of the promoter and exon 1 of this gene containing single nucleotide polymorphisms followed by treatment of the amplified fragments with restriction enzymes for allele determination. Included in the study were 84 MS patients and 125 healthy control subjects from a population of white Caucasians. We also examined 42 MS patients and 86 healthy control subjects of Shanghai Chinese origin. Significant differences in the distribution of genotypes or haplotypes of the CTLA4 gene were not observed between MS patients and control subjects in either of the two populations (P>0.05). Moreover, we were not able to confirm a previous finding of an association between relapsing-remitting MS and the heterozygous genotype A/G of CTLA4 exon 1. There was no evidence to suggest that interaction between HLA-DR2 and CTLA4 is involved in the development of MS among European Caucasians (P>0.05). Opposed to this, analysis of the Shanghai Chinese suggested presence of such interaction (P=0.02). Our results do not support the assumption that CTLA4 influences susceptibility to MS in European Caucasians. On the other hand, they raise the possibility that the development of MS in other ethnic groups involves interaction between CTLA4 and DR2.

Comparison of Whole Blood Selenium Values and Erythrocyte Glutathione Peroxidase Activities of Normal Individuals on Supplementation with Selenate, Selenite, L-Selenomethionine, and High Selenium Yeast

The selenium levels and the glutathione peroxidase activity GSH-PX of whole blood and of erythrocytes, respectively, were determined in 139 normal Danes and related to sex and smoking habits. No differences were found in relation to sex apart from a higher GSH-PX activity of females when assayed with tertiary butyl hydroperoxide. Smokers showed significantly lower selenium values than non-smokers (p<0.05), but the two groups had identical GSH-PX activities.Individuals from the above-mentioned group were divided into four groups, receiving daily oral doses of 200 μg of selenium in the form of selenite, selenate, L-selenomethionine, and selenium as contained in yeast. Whole blood selenium values and the erythrocyte glutathione peroxidase activities were determined during three months of supplementation followed by a withdrawal period of four months. Both the inorganic selenium compounds and the organic derivatives gave rise to steady state levels of GSH-PX after one month of supplementation. However, the selenium levels in the groups receiving organic selenium showed a steady rise during the whole period, whereas those supplemented with inorganic selenium leveled off after a period of one to three months. The data for smokers and non-smokers revealed identical results when organic selenium was supplemented. However, selenite gave rise to significantly higher selenium levels and GSH-PX activities in smokers than in non-smokers.Less significant (p<0.08) elevations of both parameters were also observed among the smokers in the selenate group.By taking both the selenium level and the GSH-PX activity into consideration, organic selenium (i.e.,l-(+) selenomethionine) was judged to be more bioavailable than selenite and selenate.

Selenium in chronic neurologic diseases. Multiple sclerosis and Batten's disease.

The selenium levels in whole blood and the activity of glutathione peroxidase in hematogenous cells of normal Danes have been defined taking into account sex and confounding factors such as smoking and aging. No differences related to sex could be found with regard to the selenium level, and peroxidase activity assayed with hydrogen peroxide. However, the peroxidase activity assayed with t-butyl hydroperoxide was higher in females than in males (p<.05). The peroxidase activities are dependent on age. Thus, the peroxidase levels assayed with both substrates show a minimum value in the age group from 40 to 50 yr for both smokers and nonsmokers. Smokers did show more homogeneous values as a function of age than nonsmokers. Smokers had significantly lower selenium values than nonsmokers, but glutathione peroxidase values identical with those of nonsmokers. Multiple sclerosis (MS) patients suffer from a chronic relapsing/remitting demyelinating disease. A theory explaining the pathogenesis of MS concerns increased stickiness of cellular plasma membranes, hampering normal vascular function of the brain. In agreement with that theory, the present communication demonstrates significantly lowered selenium values and lowered glutathione peroxidase activities of major types of hematogenous cells. In close agreement with these findings, hematogenous cells in MS show increased peroxidation rates. A nonblinded biochemical dietary experiment on MS patients showed that all abnormalities could be normalized by daily intake of selenium, vitamin E, and vitamin C.Batten’s disease is a recessive inherited neurodegenerative disorder clinically characterized by progressive loss of vision, epilepsy, and dementia. Neuropathologically, this disease is characterized by storage of lipofuscin in nervous tissue. We have in a few cases documented a low selenium status and low glutathione peroxidase activities of hematogenous cells. As in MS, we normalized the biochemical abnormalities by an antioxidative treatment. Like in similar Finnish studies, the biochemical parameters can be normalized. Further, the Finnish studies indicate it possible by an antioxidative treatment to inhibit progression of the mental deterioration.The data presented will be discussed in relationship both to specific pathological parameters of the diseases and to the low dietary energy expenditures of handicapped immobile patients.

Relationships between abnormal IgG index, oligoclonal bands, acute phase reactants and some clinical data in multiple sclerosis

SummaryThe IgG-index and acute phase reactants were measured and oligoclonal bands were looked for in 30 patients with clinically definite multiple sclerosis (MS) and were compared with the clinical data. IgG-index was found elevated in 77% against 22% in a comparable material of patients with other neurological diseases. Oligoclonal bands were found in 74 and 17%, respectively. No correlation was found between these parameters and age, duration of illness, disability, coefficient of progression or age of onset. A statistical evaluation defines the specificity, sensitivity and validity of the methods used. CRP could not be demonstrated in 28, the rest had normal values. C3A was normal in all cases, but appeared to be elevated a little with increasing age, and to be positively correlated to the albumin-index, indicative of a defective blood-brain barrier. No correlation was found between CRP, C3A and the clinical data.ZusammenfassungBei 30 Patienten mit klinisch sicherer Multipler Sklerose (MS) wurden IgG-Index und akute Fase Reaktanten gemessen und die Anwesenheit von oligoklonalen Bändern untersucht. Diese Daten wurden mit klinischen Daten verglichen. Der IgG-Index ist um 77% erhöht gegenüber 22% in einem Vergleichsmaterial aus Patienten mit anderen neurologischen Krankheiten. Oligoklonale Bänder wurden bei 74% bzw. 17% gefunden. Kein Zusammenhang wurde zwischen diesen Parametern und Alter, Krankheitsdauer, Invalidität, Progressionskoeffizient oder Alter bei Erkrankungsbeginn gefunden. Bei statistischer Untersuchung wurden Spezifizität, Sensitivität und Validität der verwendeten Methoden bestätigt. CRP war nicht nachweisbar bei 28, und die übrigen 2 zeigten Werte innerhalb des Normbereichs. C3A war in allen Fällen normal, war jedoch leicht erhöht in höherem Alter und auch bei höherem Albumin-Index als Parameter einer geschädigten Bluthirnschranken-Funktion. Kein Zusammenhang zwischen CRP, C3A und den klinischen Daten.