Spinocerebellar degeneration: hexosaminidase A and B deficiency in two adult sisters.

Two adult sisters had spinocerebellar degeneration. Biochemical studies revealed a very low activity of both fraction A and fraction B of the lysosomal enzyme, hexosaminidase, in serum and leukocytes. A skin biopsy showed lesions suggestive of neuronal storage disease. The disorder seems to be an adult form of GM2 gangliosidosis.

Suppression of the development of experimental allergic encephalomyelitis by suramin.

Suramin was tested for its ability to suppress experimental allergic encephalomyelitis. Prophylactic administration caused significant reduction in the severity of the disease, incidence of paralysis and cellular infiltration in nervous tissue. Therapeutic treatment with suramin also caused a reduction in the severity of the disease, the incidence of paralysis and cellular infiltration, but to a lesser extent. Significantly fewer animals were paralysed for more than two days on therapeutic treatment.

In vitro inhibition of the classical pathway of human complement by a natural microbial product, colistin sulphate.

Colistin sulphate was found to be an inhibitor of the classical pathway of the complement system. The main sites of inhibition were the interaction of EAC14 with C2 and EAC142 with C3. It also inhibited EAC14 formation from EA and C2-deficient serum, EAC1-7 formation from EAC1-3, C5, C6 and C7 and the interaction of EAC1-7 with C8 and C9, though less efficiently. It did not inhibit formation of C3/C5 convertase of the alternative pathway. The inhibition of the classical pathway was reversible since hemolytic activity was completely restored after dialysis.

In vitro inhibition of the classical pathway of human complement by polymyxin B.

Polymyxin B was found to be an inhibitor of the classical pathway of the complement system. The main sites of inhibition were the interaction of EAC14 with C2 and EAC142 with C3. It also inhibited EAC1-9 formation from EAC1-3 and C5-9 though slightly less efficiently. It did not inhibit C3/C5 convertase of the alternative pathway or its formation. The inhibition of the classical pathway was reversible since hemolytic activity was almost completely restored after dialysis.

Comparison of the spectrophotometric determination and the two-stage coagulation assay of tissue factor activity.

The tissue factor activity of human brain thromboplastin and 6 commercial thromboplastins was determined by a spectrophotometric method and a two-stage coagulation assay. The thromboplastins were incubated with an excess of Factor VII and Factor X, and the activation of Factor X was estimated from the rate of hydrolysis of the chromogenic substrate S-2222 and from the coagulation time of plasma enriched in phospholipids. The results obtained by the two methods were related linearly and showed a correlation coefficient of 0.89. The coefficient of variation was 11% in the spectrophotometric method and 25% in the two-stage coagulation assay.

The significance of the estimation of serum myoglobin in neuromuscular diseases.

The serum myoglobin concentration was determined and compared with the serum creatine kinase activity in 230 patients suffering from various neuromuscular diseases. No correlation was found between the two levels. In general serum creatine kinase activity estimation seemed more sensitive for the detection of neuromuscular disease than serum myoglobin estimation. In myotonic dystrophy, however, determination of serum myoglobin was distinctly the more sensitive method.

An improved method for the concentration of cerebrospinal fluid cells by suction tip and sedimentation chamber.

To concentrate cells from cerebrospinal fluid, a new method was developed. The technique is a modification of the cell sedimentation method of Sayk. The fluid is absorbed after passing through a Nuclepore filter, pore size 0.4 micron. With the aid of simple utensils it is possible to obtain a cell preparation of high quality using only 0.3 ml of cerebrospinal fluid. The cytomorphology is as good as that achieved by Sayk's sedimentation technique. The cell yield was determined using an accurate and precise method to estimate the number of cells present in the cerebrospinal fluid. The average cell yield is 90%, and all staining methods are applicable. The system is easily modified, and can be suited to many other fluids and purposes.

The beta 2-microglobulin content of the cerebrospinal fluid in neurological disease.

Beta 2-Microglobulin levels in the CSF and serum of 125 neurological patients were determined. The concentration of beta 2-microglobulin in CSF and serum is approximately the same, ranging from 0.6--2.3 mg/l. No clear relationship could be found between the CSF beta 2-microglobulin level on the one hand and the total protein content and white cell count on the other. There was no clear relationship between the serum beta 2-microglobulin and CSF microglobulin content. An increase of beta 2-microglobulin in CSF was found most often in cases of serious infection of the meninges or of the central nervous system. An elevated beta 2-microglobulin content can occur as the only abnormal feature of the CSF.

Central nervous system involvement in early and late syphilis: the problem of asymptomatic neurosyphilis.

Patients with syphilitic infections are at risk of development of symptomatic neurosyphilis. Adequate treatment with 2.4-7.2 x 10(6) units benzyl penicillin-G intramuscularly within 1 year after infection will rule out this risk. However, more than 1 year after infection this treatment is not fully reliable. In asymptomatic CNS involvement (asymptomatic neurosyphilis) only intravenous penicillin treatment is considered to be adequate in the prevention of neurosyphilis. In this study we redefined criteria for this condition by comparing serum and cerebrospinal fluid (CSF) samples of symptomatic neurosyphilitic patients with those of latent syphilitic patients without CNS involvement. Diagnostic criteria of the World Health Organization and of Centers of Disease Control for asymptomatic neurosyphilis (positive CSF Venereal Disease Research Laboratory (VDRL) test, combined with raised CSF cell count and/or protein content) were studied and compared with some newer parameters such as signs of intrathecal treponemal antibody production (Treponema pallidum haemagglutination assay and intrathecal Treponema pallidum assay index), immunoglobulin G (IgG) and M (IgM) index. The results of this study in 203 syphilitic patients revealed that either a positive CSF-VDRL or combination of a raised IgG and/or IgM index with an elevated CSF cell count both are useful criteria for "ruling-in" asymptomatic neurosyphilis.

Differential diagnosis of genetic disease by DNA restriction fragment length polymorphisms.

DNA restriction fragment length polymorphisms (RFLPs) are used for diagnosis of genetic disease in families known to be affected by specific disorders, but RFLPs can be also useful for the differential diagnosis of hereditary disease. An RFLP pattern represents the inheritance of chromosomal markers in a family, and such a pattern may be compatible with the inheritance of a certain disorder in that family. Probabilities to find such a pattern if the disorder were present and if it were absent can be combined with the prior probabilities of disease considered in the differential diagnosis on the basis of previous clinical and laboratory data. Bayes' theorem is used to calculate the posterior probabilities of the diseases in question. This approach is illustrated in a family suffering from either spinal muscular atrophy (an autosomal recessive disease) or Becker muscular dystrophy (an X-chromosomal disorder). Probabilities to exclude a certain disorder can be calculated in advance, as some RFLP patterns are not compatible with the presence of that disorder.

Reinvestigations into the formation and assay of C3bBbP complexes.

C3bBbP complex formation was studied by an enzyme linked immunosorbent assay (ELISA). Microtitre plates were coated with anti-P to trap the complexes and peroxidase labelled anti-C3 was used to detect them with the help of substrates of peroxidase. Incubation of normal serum pool (NSP) at 37 degrees C in the presence of high concentrations (greater than or equal to 0.5 mmol/l) of Mg2+, usually used in alternative pathway (AP) assay systems, caused the generation of C3bBbP complexes. This generation was not observed when NSP was incubated in the presence of low Mg2+ concentration (less than or equal to 0.2 mmol/l) or EDTA. The concentration of Mg2+ required for maximum complex formation was 2.0 mmol/l under the experimental conditions. Complexes could not be generated in B-depleted serum. Incubation of NSP with endotoxin or CoVF in the presence of 0.2 mmol/l Mg2+ caused the generation of the complexes. The generation was influenced by ionic strength in the incubation mixture. Endotoxin and Mg2+-dependent generation of complexes could not be detected when peroxidase-labelled anti-B was used instead of peroxidase-labelled anti-C3. Serum incubated with 0.2 mmol/l Mg2+ or EDTA apparently detected in vivo formed complexes whereas that incubated with 0.2 mmol/l Mg2+ and endotoxin reflected the complex forming capacity of the serum. The serum of a patient with Raynaud's phenomenon having 45% of normal AP activity did not show increased amounts of preformed complexes but had the ability to generate the complexes to a level of about 45% of that attainable by NSP. These observations suggest that the ELISA used here has the potential of detecting activation as well as the integrity of the AP under carefully controlled conditions.

Immunoglobulin D in cerebrospinal fluid.

Immunoglobulin D (IgD) was measured by radioimmunoassay in paired cerebrospinal fluid and serum samples from patients with various neurological diseases. The IgD index was calculated for every patient and compared with the IgG index. An increased IgD index was found in 18 out of 41 patients suffering from multiple sclerosis and in 52 out of all 122 patients investigated. An increased IgD index did not always coincide with an increased IgG index. An increased IgD index suggests an abnormal intrathecal synthesis of this immunoglobulin within the central nervous system. We conclude that the determination of IgD in the cerebrospinal fluid yields additional information on immunological reactions within the central nervous system.

Bhattacharya: a new application for quality control.

The Bhattacharya method and the 'average of normals' method for internal quality control were compared. Both are based on unselected patient test results. The Bhattacharya method is mostly used in clinical chemistry for calculation of reference intervals but could be modified for quality control procedures. Using the data of a coagulation test and stimulating systematic errors, it was concluded that the Bhattacharya method is more sensitive to expected shifts and is more flexible than the 'average of normals' method.

A cytopreparatory method for cerebrospinal fluid in which the cell yield is high and the fluid is saved for chemical analysis.

A method for the concentration of cells from cerebrospinal fluid is described. An adaptation of a commercial cytochamber, consisting of a holder that fixes a disposable chamber directly on a microscope slide, was used. The cells were spun down in a conventional swing-out centrifuge, which was provided with a bucket for the cytochamber system. After removing most of the supernatant with a pipette, the remaining fluid was absorbed by means of a suction device consisting of a disposable pipette tip covered with a piece of Leukopor and filled with Sephadex G10 beads. The method gives a high recovery of cells (90%), together with a good preservation of cell morphology, and leaves about 80% of the fluid available for analysis of the soluble components.