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Biomedical subjects

T Mathiesen

Publications and source records attributed to T Mathiesen.

61 records · Page 4Linked to original sources

IgG subclass reactivity against human immunodeficiency virus (HIV) and cytomegalovirus in cerebrospinal fluid and serum from HIV-infected patients.

Cerebrospinal fluid (CSF) and serum samples from 17 patients seropositive for the human immunodeficiency virus (HIV) were analysed for specific IgG1-4 against HIV and cytomegalovirus (CMV). Measles IgG was studied as a reference to detect blood-brain barrier (BBB) defects. All patients had IgG1 antibodies against HIV in both CSF and serum, and all had CMV IgG1 in serum (16 in CSF). Anti-HIV IgG was synthesised intrathecally in 11 patients, IgG3 in three patients, and IgG4 in three patients. Intrathecal production of anti-CMV IgG1 was found in three patients, IgG2 in one, IgG3 in three, and IgG4 in one. Intrathecal anti-HIV IgG synthesis could be demonstrated in all stages of the disease. Analysis of all IgG subclasses allowed intrathecal HIV and/or IgG production to be detected also in patients in whom intrathecally synthesised IgG was restricted to IgG2, 3, or 4. The expression of HIV-specific IgG subclasses in CSF and serum was more restricted in AIDS patients than in HIV-infected persons without clinical AIDS. On the contrary, the largest number of CMV-specific IgG subclasses was found in AIDS patients. Intrathecal HIV or CMV IgG subclass production was seen both with and without neurological symptoms. The peripheral T4 cell counts were not obviously related to neurological symptoms. Even patients with low peripheral T4 cell counts had evidence of intrathecal antibody synthesis against HIV and sometimes CMV, suggesting a retained helper function of T cells in the central nervous system.

AIDS-Related Complex↗

Specific IgG subclass reactivity in herpes simplex encephalitis.

Serum and cerebrospinal fluid (CSF) samples from 19 patients with a previous diagnosis of herpes simplex virus encephalitis (HSVE), from 14 patients with a previous diagnosis of non HSVE encephalitis and from 21 healthy subjects were examined to detect IgG subclasses 1-4 reactive with herpes simplex virus (HSV), cytomegalovirus (CMV) and varicella zoster virus (VZV). Antibodies to HSV were detected in CSF and serum from the 14 HSVE-patients with a reactivated HSV infection and from 3 of the 5 patients with a primary HSV infection. The predominant subclass pattern was an early HSV-specific IgG1 rise, followed by IgG3 and, more seldom, IgG4; HSV IgG2 was rarely seen. In HSVE patients, HSV IgG3 was absent in early samples and usually appeared 10-20 days after onset of disease. In 14 out of 16 seropositive healthy controls, on the other hand, HSV IgG3 was present in the CSF. Rising VZV IgG levels in serum and CSF were found in 11 HSVE patients. Eight of them showed signs of intrathecal VZV IgG1 synthesis. The VZV IgG reactivity was restricted to IgG1 in 7 of these whereas the HSV IgG subclass response also included IgG3 or 4. The appearance of several HSV IgG subclasses appeared to serve as a marker of HSV infection in spite of the serological VZV reaction, usually restricted to VZV IgG1. Intrathecal synthesis of the quantitatively minor HSV IgG3 and 4 subclasses was detected earlier than intrathecal synthesis of total HSV IgG, dominated by IgG1 in 4 patients with HSVE.

Encephalitis↗

Acid hydrolysis of serum samples to increase detection of HIV antigen.

Sera from 32 HIV-infected patients and 20 controls were assayed for HIV antigen (HIV-Ag) and antibodies following acid hydrolysis. Acid hydrolysis, followed by neutralization immediately prior to the assay, was found to be a simple means to solubilize immune complexes and allowed recovery of 40-50% of complexed antigen. Following acid hydrolysis, HIV-Ag levels rose or became detectable in 22/32 patients and HIV IgG1-4 levels rose in 17/20 patients studied. The results show that complexed HIV-Ag may evade detection in HIV-infected patients.

Acquired Immunodeficiency Syndrome↗

Combination ELISAs for antiviral antibodies in CSF and serum in patients with neurological symptoms and in healthy controls.

A combination enzyme-linked immunosorbent assay (ELISA) was designed to improve the estimation of serum: cerebrospinal fluid (CSF) antiviral IgG ratios. Microplate wells were coated with five different virus antigens. Serum and CSF from 66 patients referred for CSF serology and from 21 healthy controls were studied. In a comparison with serum: CSF IgG titre ratios, absorbance ratios were found to be suitable for the evaluation of intrathecal antiviral IgG synthesis. A slight blood-brain barrier (BBB) disturbance affected only the passage of albumin over the BBB, whereas a more pronounced BBB defect resulted in increased IgG levels in the CSF. Intrathecal antiviral IgG synthesis was demonstrated in 15 patients with viral CNS infections or inflammatory diseases. Very high serum: CSF antiviral IgG titre ratios and absorbance ratios, found in six patients, were interpreted as signs of diminished IgG passage over the BBB due to impaired CSF circulation.

Adult↗

Neutralization capacity and antibody dependent cell-mediated cytotoxicity of separated IgG subclasses 1, 3 and 4 against herpes simplex virus.

IgG subclasses 1, 3 and 4 in sera from herpes simplex virus type 1 (HSV-1) seropositive donors were separated and their functions assayed. The main neutralizing activity to HSV-1 was found in the IgG1 fractions. Both IgG3 and IgG4 possessed higher neutralizing titres than IgG1 in relation to the respective HSV IgG subclass enzyme-linked immunosorbent assay (ELISA) titre. Addition of complement resulted in a strong enhancement of IgG3 neutralizing activity. HSV neutralizations by IgG1 and, surprisingly, IgG4 were also somewhat enhanced by complement. With the addition of complement, the contribution to neutralizing activity of IgG3 was calculated to increase from 31 to 40% of total IgG in HSV neutralization in native sera. The avidities of the IgG fractions to HSV glycoprotein C (gC) were estimated in a few sera but could not be correlated to neutralization results. Antibody dependent cell-mediated cytotoxicity (ADCC) was detectable mainly in IgG1 and 3 fractions of sera with high anti-HSV antibody titres.

Antibody Affinity↗

A prognostic algorithm for assessment of subcapital femoral neck fractures.

A new method for prognostication of non-union in subcapital femoral neck fractures is presented. From routine pre- and post-operative films from 112 patients with Garden stage 2, 3, and 4 fractures 4 parameters were obtained: Cranial displacement, orientation of the nail in the femoral head, depth of nail inserted, and attainment of perfect reduction. These 4 variables were combined into a simple algorithm capable of non-union prediction at various levels of certainty (74-100%).

Adult↗