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Biomedical subjects

N M Papadopoulos

Publications and source records attributed to N M Papadopoulos.

At least 37 records · Page 2Linked to original sources
PubMed1987

A comparison between chemical analysis and magnetic resonance imaging with the clinical diagnosis of multiple sclerosis.

Ninety-five patients suspected of having multiple sclerosis (MS) were evaluated by medical history and neurologic examination. Based on this evidence they were divided into three groups: clinically definite MS, not-definite MS, and not MS. The adjunct tests, chemical analysis, and magnetic resonance imaging (MRI), were also performed to assess the diagnosis of MS. Chemical analyses of paired serum and cerebrospinal fluid (CSF) samples were performed to identify oligoclonal immunoglobulin bands and to estimate both the albumin quotient and the IgG index. A positive correlation was found between the chemical test results and definite MS in 73 of 73 cases. In 11 of 12 cases of not-definite MS the chemical results were positive for MS. A positive correlation was also found between ten of ten cases that were not MS and negative chemical test results. MRI scans were positive for MS in 48 of 51 clinically definite MS cases and in 4 of 4 not-definite MS cases. MRI scans were negative for MS in five of six cases that were not MS. These findings demonstrate that combined determinations of serum and CSF proteins by simple zone electrophoresis and commercial immunochemical tests can be useful laboratory aids in the diagnosis of MS. The MRI scans provide additional evidence to support the diagnosis of MS.

Albumins↗
PubMed1986

Cryoglobulinemia in autoimmune rheumatic diseases. Evidence of circulating monoclonal cryoglobulins in patients with primary Sjögren's syndrome.

The incidence and nature of cryoglobulins, as well as their correlation with the clinical and serologic picture of Sjögren's syndrome (SS), were studied in the sera of 30 consecutive primary SS patients. Sera from 29 patients with systemic lupus erythematosus, 58 patients with rheumatoid arthritis, and 125 healthy blood donors were also studied. It was shown that one-third of the patients with SS had cryoglobulinemia. These cryoglobulins were mixed monoclonal IgM immunoglobulins, whereas those observed in systemic lupus erythematosus and rheumatoid arthritis patients were mixed polyclonal. The nature of the cryoglobulins was demonstrated using high-resolution electrophoresis combined with immunofixation. The presence of cryoglobulins in the sera of SS patients correlated with extraglandular disease and with antibodies to Ro (SS-A) and IgM rheumatoid factor. SS patients with cryoglobulins had lower serum C4 levels than did patients without cryoglobulins. These findings suggest that SS expresses, in addition to polyclonal B cell hyperreactivity, a monoclonal process in the absence of lymphoid neoplasia. Further, they show that the extraglandular manifestations of the syndrome may be due to an immune complex-mediated pathology.

Adult↗
PubMed1986

Secretory leukemic B cells express T cell markers in vitro. A phenomenon suppressed by TPA.

Immunological and biochemical markers of leukemia/lymphoma cells have provided valuable insight into hematopoietic malignancy and normal differentiation. The general assumption is that as early lymphoid cells become committed towards terminal differentiation they lose their capacity for bimodal differentiation and cells become restricted to B or T cell development and function. We have observed that phenotypically "late" leukemic B cells close to secretory stage can spontaneously express mature T cell antigens (T11, T4 and T8) after culture in vitro. In further studies of these cells, it was found that the biochemical marker lactate Dehydrogenase (LD) follows the intermediate pattern expressed by thymocytes rather than that of typical B cells. The expression of T cell antigens can be blocked by incubating these cells with the phorbol ester TPA (12-0-tetradecanoyl phorbol 13 acetate) which promotes unidirectional B cell maturation to plasmacytoid cells in a way that mimics normal B cell differentiation. These observations indicate that presecretory malignant B cells are still programmed to express T cell biochemical and antigenic markers and this expression can be influenced by environmental conditions in vitro.

Antigens, Surface↗
PubMed1986

Cryoglobulinemia in primary Sjögren's syndrome: a monoclonal process.

Patients with primary Sjögren's syndrome have in their sera and urine free light chains or monoclonal immunoglobulins. In addition, they have mixed monoclonal (IgM kappa) cryoglobulinemia, which is associated with extraglandular disease and greater incidence of autoantibodies. In the present study, it is demonstrated by a high resolution agarose gel electrophoresis, combined with immunofixation, that nine patients with primary Sjögren's syndrome have mixed monoclonal (IgM kappa) cryoglobulins, in contrast to those observed in five patients with secondary Sjögren's syndrome (Sjögren's syndrome and rheumatoid arthritis), 13 patients with rheumatoid arthritis and six patients with systemic lupus erythematosus, which were mixed polyclonal.

Antibodies, Monoclonal↗
PubMed1985

Abnormal cerebrospinal fluid protein indices in schizophrenia.

Determinations of albumin and immunoglobulin G (IgG) were performed in paired cerebrospinal fluid (CSF) and serum samples from 24 subjects with schizophrenia. These determinations allowed calculation of two indices, one that is an indicator of integrity of the blood-brain barrier and the other a measure of selective IgG production within the central nervous system (CNS). In comparison with previously determined reference values, 7 of 24 (29%) subjects showed increased blood-brain barrier permeability, and 8 of 24 (33%) demonstrated elevated endogenous CNS IgG production. One of these eight also demonstrated oligoclonal banding on high-resolution protein electrophoresis of the CSF.

Adolescent↗
PubMed1985

Levels of lipoprotein Lp(a) decline with neomycin and niacin treatment.

Total and low density lipoprotein cholesterol concentration reduction in patients with markedly increased levels of these substances, leads to a decline in the incidence of myocardial infarction and death. A unique cholesterol-rich lipoprotein, lipoprotein Lp(a), has been identified which not only can be confused with low density lipoproteins, but has also been associated with premature cardiovascular disease. Using the cholesterol-lowering drugs neomycin and niacin in 14 type II hyperlipoproteinemic subjects, we determined the effect of lipid-lowering therapy on lipoprotein Lp(a) concentrations. Neomycin (2g/day) reduced low density lipoprotein cholesterol and lipoprotein Lp(a) concentrations by 23% and 24%, respectively. Combination therapy with neomycin (2 g/day) and niacin (3 g/day) induced a 48% decline in low density lipoprotein cholesterol levels and a 45% reduction in the concentration of lipoprotein Lp(a). These changes in lipoprotein Lp(a) levels were associated with a striking decline in the intensity of the slow pre-beta-lipoprotein fraction determined Lp(a) by lipoprotein electrophoresis. This slow pre-beta-lipoprotein fraction contained Lp(a) determined by immunofixation. These observations indicate that lipoprotein Lp(a) concentrations can be altered pharmacologically and that the progression of cardiovascular disease may be altered through changes in lipoprotein (a) levels.

Adult↗
PubMed1985

Oligoclonal immunoglobulins in patients with the acquired immunodeficiency syndrome.

Analysis of serum samples from patients with the acquired immunodeficiency syndrome (AIDS) was performed by high-resolution zone electrophoresis. A high incidence of monoclonal and oligoclonal immunoglobulins was detected in the sera of 24/27 patients with Kaposi's sarcoma and in 2/15 patients with opportunistic infections. The presence of monoclonal bands was independent of whether or not the patients had experienced an opportunistic infection. These findings indicate a monoclonal or oligoclonal B-cell activation occurring in a much higher frequency in AIDS patients with Kaposi's sarcoma, thus suggesting that similar mechanisms may be operative in the malignant or pseudomalignant proliferation of B-cells and endothelial cells in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Demonstration and identification of monoclonal proteins in the urine of patients with Sjögren's syndrome.

Fresh sera and concentrated urine from 17 patients with primary Sjögren's syndrome (SS) were fractionated by high-resolution agarose electrophoresis to investigate the presence of monoclonal immunoglobulins or their components. Homogeneous protein bands were found in the gamma-globulin region in 47% of serum samples and 76% of urine specimens of all patients tested. These monoclonal proteins were detected more often in patients with extraglandular SS (77% in serum, 100% in the urine) than in patients with glandular SS (14% in serum, 43% in the urine). Immunofixation electrophoresis showed that the majority of these monoclonal proteins were free kappa or lambda light chains. Fractionation of unconcentrated parotid salivas from five SS patients failed to reveal the presence of monoclonal light chains or immunoglobulins. The present findings further substantiate our previous observation that a monoclonal process coexists with the polyclonal activation in SS patients.

Adult↗
PubMed1984

Paraproteins in the spinal fluid of patients with paraproteinemic polyneuropathies.

High-resolution agarose gel electrophoresis, combined with immunofixation electrophoresis, was used to detect and identify immunoglobulins in the cerebrospinal fluid of six patients with paraproteinemic polyneuropathy. In four patients with serum IgM kappa monoclonal protein, we found a discrete band in the cerebrospinal fluid identified also as IgM kappa; one patient with serum IgG kappa had an IgG kappa cerebrospinal fluid band, and one patient with serum IgA kappa had an IgA kappa monoclonal band in the cerebrospinal fluid. The permeability of the blood-cerebrospinal fluid barrier was increased 3 to 10 times in all these patients. The findings indicate that in patients with paraproteinemic polyneuropathy, the increased permeability of the blood-cerebrospinal fluid barrier results in influx of serum proteins into the cerebrospinal fluid, including high-molecular-weight IgM. Because monoclonal IgM, unlike monoclonal IgG and IgA, is not found in the cerebrospinal fluid of neurologically intact patients, its presence in the cerebrospinal fluid of patients with paraproteinemias should lead the physician to suspect neurological involvement and can be of diagnostic value.

Adult↗
PubMed1984

The presence of immunoglobulin D in endocrine disorders and diseases of immunoregulation, including the acquired immunodeficiency syndrome.

Immunoglobulin D (IgD) was determined by double diffusion in the serum from 26 patients with endocrine disorders and diseases of immune imbalance along with controls. IgD was detected in the serum of nine patients that included two with primary parathyroidism, one with insulin-resistant diabetes, four with immunodeficiencies, and two with Hodgkin's disease. IgD was absent in the serum of seven patients with the same diagnoses after treatment. IgD was present in the serum of the majority of acquired immune deficiency syndrome patients (in eight of ten cases). The presence of IgD in the serum of these patients suggests that it plays a role in receptor-mediated events.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Combined immunochemical and electrophoretic determinations of proteins in paired serum and cerebrospinal fluid samples.

Albumin and immunoglobulin G were simultaneously determined in paired serum and cerebrospinal fluid samples from healthy volunteers. The albumin quotient and the IgG index were calculated to establish normal values. High-resolution electrophoresis was also performed with the same samples and the electrophoretic patterns were correlated with the numerical values to improve the reliability of the test results. Representative examples from abnormal conditions are also shown, to illustrate the increased accuracy and useful applications of this combined analysis in the diagnosis of neurological conditions.

Adult↗
PubMed1983

The effect of growth hormone administration on lipids and lipoproteins in growth hormone-deficient patients.

Plasma lipids, lipoproteins, and lipoprotein cholesterol levels were studied in a group (n = 8) of prepubertal growth hormone-deficient patients before and after growth hormone (GH) administration. Determination of plasma lipoproteins by a sensitive agarose gel electrophoretic technique demonstrated: (a) in the patients with two prebeta bands an intensification of the fast prebeta lipoprotein fraction after growth hormone administration; and (b) in the patients with one prebeta band the appearance of a second prebeta band after growth hormone administration. The mean (+/- SD) plasma triglyceride level before GH was 86 +/- 60 mg/dl and 158 +/- 95 mg/dl after GH (P less than 0.01). Mean (+/- SD) plasma cholesterol level before GH was 196 +/- 25 mg/dl and 174 +/- 28 mg/dl after GH (P less than 0.05). High-density lipoprotein cholesterol concentrations decreased significantly (P less than 0.001) from mean (+/- SD) 55 +/- 12 mg/dl before GH to 37 +/- 10 mg/dl after GH. Very-low-density lipoprotein cholesterol concentrations increased significantly (P less than 0.05) from mean (+/- SD) 13 +/- 12 mg/dl before GH to 23 +/- 15 mg/dl after GH. Low-density lipoprotein cholesterol concentrations decreased (N.S.) from mean (+/- SD) 123 +/- 15 mg/dl before GH to 114 +/- 15 mg/dl after GH. These lipid and lipoprotein changes could be mediated through the insulin antagonism, hyperinsulinemia, and a decrease in lipoprotein lipase activity caused by growth hormone.

Adolescent↗
PubMed1983

A unique protein in normal human cerebrospinal fluid.

On analysis of cerebrospinal fluid (CSF) samples from normal volunteer donors by high-resolution zone electrophoresis on agarose gel, an electrophoretically homogeneous protein band consistently appeared in the gamma-globulin region. Application of immunofixation electrophoresis in attempts to identify the band with use of monospecific antibodies against individual human serum proteins and against heavy- and light-chain immunoglobulins as well as polyvalent antisera did not produce a positive immunoprecipitation reaction with the protein band. The serum samples from these subjects did not show similar bands. Therefore, we conclude that this protein band is a normally occurring protein that is unique to CSF.

Adult↗
PubMed1983

High incidence of free monoclonal lambda light chains in the sera of patients with Sjogren's syndrome.

Sjogren's syndrome presents a wide spectrum of disease manifestations ranging from benign to malignant lymphoproliferation. Sera from 21 patients with primary Sjogren's syndrome, 63 patients with other autoimmune rheumatic diseases, and 140 normal controls were studied by using high-resolution gel electrophoresis combined with immunofixation and specific absorption studies. Two-thirds of the sera from Sjogren's syndrome patients contained free monoclonal lambda light chains. In addition, one patient with Sjogren's syndrome and pseudolymphoma had a circulating monoclonal IgM-lambda immunoglobulin. In contrast, only 16% of the patients with other autoimmune diseases and 5% of normals had monoclonal bands; none of the other patients studied exhibited monoclonal-free lambda light chains in their serum. Our findings suggest that the monoclonal process in Sjogren's syndrome starts early in the disease process in a subset of B cells.

Antibodies, Monoclonal↗
PubMed1983

Heterogeneity of lipoprotein electrophoretic patterns in patients with type IIa hyperlipoproteinemia.

Previous evaluations of plasma lipoproteins from patients with type IIa hyperlipoproteinemia have demonstrated quantitative but not qualitative differences from lipoproteins isolated from normal subjects. Using a reproducible, sensitive, high-resolution agarose gel electrophoretic system, we evaluated the plasma lipoprotein of 22 consecutive, untreated, unrelated patients with type IIa hyperlipoproteinemia. Five distinct electrophoretic patterns were observed. This electrophoretic heterogeneity in type IIa hyperlipoproteinemia reflects subtle charge differences in the lipoproteins from these patients, which were not detected with paper electrophoresis or with lipoprotein quantification. There was little, if any, difference in total plasma cholesterol, low- or very-low-density lipoproteins, plasma triglycerides, or concentrations of apolipoproteins A-I, A-II, B, C-II, or E in these subgroups. However, unique clinical features were correlated with the electrophoretic patterns. These findings support the concept that the type IIa hyperlipoproteinemic phenotype includes several molecular defects that are reflected in subtle differences in lipoprotein charge.

Adult↗