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Biomedical subjects

J Petersen

Publications and source records attributed to J Petersen.

At least 253 records · Page 14Linked to original sources
PubMed1984

Secretion of immunoglobulins and IgM rheumatoid factor by pokeweed mitogen-induced blood lymphocytes: an evaluation by plaque forming cell assays.

The numbers of pokeweed mitogen (PWM)-induced IgM-, IgG- and IgA-secreting cells (SC) in mononuclear cell cultures from patients with seropositive and seronegative rheumatoid arthritis (RA) were reduced compared to those of control persons. Significant numbers of IgM rheumatoid factor (RF)-SC were only found in PWM-induced cultures from patients with seropositive RA (median: 7 IgM RF-SC/10(6) and controls greater than or equal to 50 years (median: 6 IgM RF-SC/10(6). The ratio of IgM RF-SC to total IgM-SC (RF/IgM-SC ratio) was significantly higher in patients with seropositive RA (median: 0.6%) than in controls greater than or equal to 50 years (median: 0.1%). Patients with seropositive RA and RF/IgM-SC ratios above 0.5% had higher Waaler-Rose titers than those with ratios under 0.5%. Our results indicate that secretion of Ig by PWM-induced blood lymphocytes is suppressed in patients with RA compared to controls; in seropositive RA a higher fraction of in vitro activated IgM-SC secrete IgM RF as compared to controls and patients with seronegative RA.

Adult↗
PubMed1984

Spontaneous and induced immunoglobulin secretion by synovial fluid B lymphocytes in rheumatoid arthritis.

The functional properties of B lymphocytes in synovial fluid (SF) from patients with rheumatoid arthritis (RA) were analysed by means of a reverse haemolytic plaque forming cell (PFC) assay. SF mononuclear cells spontaneously secreted IgG, but little IgM or IgA. The SF cells failed to respond to the polyclonal B cell activators pokeweed mitogen (PWM) and Epstein-Barr virus. However, SF B cells cocultured with autologous T lymphocytes from the blood and stimulated with PWM secreted IgG but little IgM or IgA. The PFC responses of blood B cells cocultured with autologous SF T cells in the presence of PWM were low; irradiation of the T cells increased the blood B lymphocyte responses, but the differences were not statistically significant. It is concluded that suppressor SF T cells may be partly responsible for the poor response of SF B cells to PWM.

Adult↗
PubMed1984

Spontaneous in vitro immunoglobulin secretion at the diagnosis of insulin-dependent diabetes.

Blood mononuclear cells obtained from 17 newly diagnosed insulin-dependent diabetic (IDDM) patients treated with insulin for 5-7 days were assessed for the number of spontaneous and pokeweed mitogen (PWM)-stimulated immunoglobulin-secreting cells in a reverse haemolytic plaque assay. The spontaneous in vitro immunoglobulin secretion was evanescent and decreased in individual patients within 1-4 months of insulin treatment. Compared to matched controls, 53% (9/17) of the IDDM patients had an elevated spontaneous secretion of immunoglobulin, 41% (7/17) for IgG, 35% (6/17) for IgM, and 35% (6/17) for IgA. The quantities of PWM-stimulated IgG, IgM, or IgA secreting cells in IDDM were comparable to the controls. The IDDM patients with spontaneous immunoglobulin secreting cells had higher fasting C-peptide levels compared to the patients with immunoglobulin-producing cells within the normal range (P less than 0.05). The average titre of islet cell cytoplasmic antibodies was 1:26 in (9 out of 9 were positive) patients with, compared to 1:1 in patients (4 out of 8 were positive) without spontaneous secretion (P = 0.025). These results suggest that the clinical onset of IDDM is associated with a polyclonal B lymphocyte activation and that higher levels of fasting C-peptide islet cell antibodies are associated with this immunoregulatory abnormality.

Adolescent↗
PubMed1984

Synovial fluid and blood monocytes/macrophages in rheumatoid arthritis. Influence on polyclonal activation of autologous B lymphocytes.

The regulatory role of synovial fluid monocytes/macrophages from patients with rheumatoid arthritis in terms of B lymphocyte activation was evaluated by a reverse haemolytic plaque-forming cell (PFC) assay. Macrophage-depleted blood mononuclear cells (BMC) failed to respond to pokeweed mitogen (PWM). With autologous synovial fluid macrophages added, the PFC responses of macrophage-depleted BMC increased, and optimal concentration for full restoration of the PFC responses ranged from 8 to 35%. Synovial fluid mononuclear cells (SMC) as well as macrophage-depleted SMC were not able to respond to PWM. Addition of irradiated autologous blood macrophages to SMC did not increase the SMC PFC responses. It is concluded that the regulatory properties of synovial fluid macrophages do not explain the low PFC response of SMC to PWM.

Adult↗
PubMed1983

Colony formation by subpopulations of human T lymphocytes. III. Antigenic phenotype and function of colony-forming cells, colony cells, and their expanded progeny.

The antigenic phenotype of individual PHA-induced T lymphocyte colonies was studied with a direct immunofluorescence technique using fluorescein-labeled anti-Leu-2a and anti-Leu-3a antibodies. Of the colonies grown from mononuclear peripheral blood cells 85% were Leu-3a+ (inducer/helper phenotype), 12% were Leu-2a+ (suppressor/cytotoxic phenotype), and 3% contained equal numbers of Leu-2a+ and Leu-3a+ cells. Fluorescence-activated cell sorter (FACS) separated T-cell subsets showed that Leu-2a+ cells and Leu-3a+ cells form exclusively Leu-2a+ and Leu-3a+ colonies, respectively. Leu-3a+ cells formed colonies in both the absence and presence of conditioned medium (PHA-CM), whereas colony formation by Leu-2a+ cells was absolutely dependent on PHA-CM. Mixing experiments with FACS-separated T-cell subsets showed that Leu-2a+ cells inhibit colony formation by Leu-3a+ cells in a cell dose-dependent manner both in the presence and absence of PHA-CM. Phenotype analysis of individual colonies from mixing experiments strongly suggested monoclonal proliferation in the present colony assay system. The majority of expanded T-cell colonies showed helper activity in a reverse hemolytic plaque-forming B-cell assay, although to a lesser degree as compared to that of freshly isolated T lymphocytes.

Antibody Formation↗
PubMed1983

Diagnostic value of urinary N-acetyl-beta-D-glucosaminidase, its isoenzymes and the fractional excretion of sodium following renal transplantation.

Daily total urine N-acetyl-beta-D-glucosaminidase activity, isoenzyme profile and fractional excretion of sodium were measured in 13 consecutive renal transplant patients. Rejection episodes were clinically diagnosed in 12 patients, 11 of whom (92%) showed an increased enzymuria either before or during the onset of clinical signs. The ratio of the two major isoenzymes (A/B) fell during 10 episodes (83%) and in six of these (50%) increased levels of the minor isoenzyme forms were observed. Increased fractional excretion of sodium was associated with nine (75%) of the episodes. Increased fractional excretion of sodium with a raised total enzymuria accompanied by a reduced A/B ratio and an increased proportion of the minor isoenzyme forms occurred in eight (67%) of the rejection episodes. The use of these measurements in the diagnosis of episodes of acute rejection in renal transplantation is discussed.

Acetylglucosaminidase↗
PubMed1983

Storage of protein A-conjugated sheep erythrocytes for use in plaque-forming cell (PFC) assays.

Sheep red blood cells conjugated with protein A from Staphylococcus aureus were frozen in liquid nitrogen. After thawing these cells were used as indicator cells in a plaque-forming cell assay visualizing human B lymphocytes secreting IgG, IgM or IgA. The thawed erythrocytes performed as well in the assay as erythrocytes freshly conjugated with protein A. Recovery of conjugated erythrocytes after freezing and thawing averaged 66%. By the method described indicator cells for a number of PFC assays may be prepared in bulk, frozen in suitable portions and thawed when needed. This prevents possible batch-to-batch variations and saves time.

Animals↗
PubMed1983

The long-term clinical course of systemic lupus erythematosus in end-stage renal disease.

In an attempt to define the long-term clinical course of systemic lupus erythematosus followed by end-stage renal disease, we studied 28 patients with lupus nephritis at Stanford University between January 1969 and December 1980. The clinical and serologic manifestations of both renal and nonrenal disease improved with long-term hemodialysis despite the withdrawal of immunosuppressive drugs in almost all the patients. Rehabilitation was excellent, and a return to normal physical activity was generally the rule. The mortality rate was low (6 of the 28 patients died), but death occurred primarily in patients receiving high doses of prednisone. Recovery from renal failure and discontinuation of dialysis were not rare (eight patients recovered) despite the reduction in immunosuppressive drugs. Renal transplantation was also well tolerated. We found the long-term clinical course of these patients to be comparable to that of patients with end-stage renal disease associated with disorders other than systemic lupus erythematosus.

Adolescent↗
PubMed1983

Femoral hypoplasia-unusual facies syndrome in infants of diabetic mothers.

Three children with the femoral hypoplasia-unusual facies syndrome are described. Two had the characteristic facial pattern of upslanted palpebral fissures, long philtrum with thin upper lip, micrognathia, and hypoplastic alae nasi. The other, an infant girl who died within 24 hours after birth, had a cleft lip, which distorted some of the other features. She also had a cleft palate, as did one of the two older boys. All three children had ear defects, upper limb involvement, and rib, vertebral, lower extremity, and genitourinary tract abnormalities. The infant girl died of lung hypoplasia associated with dysplastic kidneys and widely patent ductus arteriosus. All three were infants of diabetic mothers, one mother having developed overt diabetes in the first trimester of pregnancy. A literature review of 36 reported cases of FH/UFS revealed 12 individuals who were IDMs, establishing a strong relationship of the syndrome with maternal diabetes. A multifactorial inheritance model fits with the reported patients, with the relationship to diabetes, and with the similarity of FH/UFS to caudal regression, another condition related to maternal diabetes.

Abnormalities, Multiple↗
PubMed1983

IgG rheumatoid factor-secreting lymphocytes in rheumatoid arthritis: evaluation of a haemolytic plaque-forming cell technique.

A haemolytic plaque-forming cell (PFC) assay detecting human B lymphocytes secreting IgG rheumatoid factor (RF) was established using sheep erythrocytes (SRBC) sensitized with rabbit IgG, developing rabbit anti-human IgG, and complement. IgG-RF PFC were only demonstrated with IgG-depleted guinea-pig serum as the source of complement. Cells spontaneously secreting IgG-RF were found among synovial fluid mononuclear cells (mean, 134/10(6)) and synovial tissue mononuclear cells (mean, 1775/10(6)) from patients with rheumatoid arthritis, whereas few were recorded among blood lymphocytes (mean, 3/10(6)). The experiments revealed that the RF-IgG PFC were protein-synthesizing B lymphocytes. The antibody specificity of the secreted IgF-RF was verified by the inhibitory effect of exogenous human and rabbit IgG on PFC formation.

Animals↗
PubMed1983

Suppression of B lymphocytes in mature newborn infants.

The ability of cord blood lymphocytes to secrete immunoglobulins during in vitro culture was investigated by means of a reverse hemolytic plaque forming cell (PFC) assay. Mononuclear cord blood cells did not differentiate into immunoglobulin-secreting cells after stimulation with the polyclonal B lymphocyte activator pokeweed mitogen (PWM), contrary to the findings in normal adults. Mononuclear cord blood cells were then separated into T-enriched and T-depleted blood lymphocyte subsets. When these were co-cultured, the PWM-induced immunoglobulin secretion was still low; following irradiation of the T-enriched cells, the numbers of IgM-PFC but not of IgG- or IgA-PFC increased considerably. The effect of irradiation of the T-enriched cells on the PWM-induced IgM response was dose-dependent, with maximal effect at 2500 rad. It is concluded that the low PWM responses obtained using cord blood lymphocytes are in part due to suppression by radiosensitive T suppressor cells. Following removal of this suppression by means of irradiation, B lymphocytes can be induced to secrete IgM, but not IgG or IgA.

Adult↗