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Biomedical subjects

J B Peter

Publications and source records attributed to J B Peter.

At least 109 records · Page 6Linked to original sources
PubMed1990

Dietary regulation of fibrinolytic factors.

W examined the short-term effects of a high-complex carbohydrate, low fat diet on the plasmin-dependent fibrinolytic pathway. A population of 27 adult American Caucasians exposed to the diet for 3 weeks showed highly significant reductions in the levels of plasminogen (P = 0.0001), tissue plasminogen activator (tPA) (P = 0.0001) and plasminogen activator inhibitor (tPAI) (P = 0.0017). Fibrinogen levels also decreased, but the changes did not reach statistical significance (P = 0.07). In contrast, the levels of the Lpa(a) lipoprotein, a potential inhibitor of fibrinolysis, remained remarkably constant despite a marked decrease in the levels of apolipoprotein B, a major constituent of Lp(a). Correlations between the levels of tPA, tPAI and plasma triglyceride were observed among the individuals both before and after the dietary challenge. Although the mechanisms responsible for the effects are unknown, the dramatic responsiveness of the thrombolytic pathway to dietary challenge is likely to be of importance in understanding the etiology of coronary artery disease and other vascular disorders.

Apolipoproteins↗
PubMed1990

Detection of HIV DNA in peripheral blood by the polymerase chain reaction: a study of clinical applicability and performance.

We evaluated the applicability and performance of the polymerase chain reaction (PCR) in a clinical setting in two independent studies. In a study of its applicability, the specificity and sensitivity of PCR for detection of HIV DNA were 100% (225 out of 225 seronegative, low-risk individuals tested negative) and 94% (67 out of 71 seropositive individuals tested positive), respectively. In a second study evaluating the performance of PCR, seven out of 474 (1.5%) antibody-negative specimens were found to be positive, 149 out of 151 (99%) antibody-positive specimens were positive, and 12 out of 13 (92%) antibody-indeterminate specimens were negative for HIV DNA. The results from these studies show that PCR in a clinical environment is specific and sensitive. PCR is also useful in the detection of HIV infection in the absence of HIV-specific antibody and the resolution of equivocal antibody results.

DNA, Viral↗
PubMed1990

IgG subclasses in human chronic schistosomiasis: over-production of schistosome-specific and non-specific IgG4.

IgG subclasses were determined quantitatively in sera from 63 Egyptian men who were infected with Schistosoma mansoni. Total and antigen-specific IgG was measured pre- and post-treatment. Total IgG subclass antibodies were determined by immunoradiometric assay (IRMA) using monoclonal antibodies (MoAbs). The anti-worm and anti-egg specific S. mansoni IgG subclass antibodies were quantitatively measured by ELISA using specific MoAbs and standards obtained by affinity chromatography. Our data show that total IgG of the patients was elevated in the range of two to three times above normal. The magnitude of increase differed markedly among the four subclasses of IgG. The IgG1, IgG2 and IgG3 concentrations were approximately two to four times higher than normal, whereas the IgG4 concentrations was 20 times normal (9000 mg/l). IgG1 and IgG4 tended to dominate the IgG subclass distribution of anti-soluble worm antigen preparation (SWAP) antibodies followed by IgG2 and IgG3. On the other hand, IgG1 and IgG2 dominated the IgG subclass distribution of anti-soluble egg antigen (SEA) antibodies. As with IgG1, IgG2 and IgG3, most IgG4 was non-specific. The role of IgG subclasses in the pathogenesis of schistosomiasis is not clear. However, the high concentration of IgG4 might act as IgE blocking antibody, possibly as anti-idiotypes that may play a role in down-regulation of the immune system when it is challenged with an excess of antigen.

Adolescent↗
PubMed1990

Ibuprofen meningitis.

Explore the source record for details and available documents.

Antigen-Antibody Complex↗
PubMed1990

Elevated serum levels of soluble interleukin 2 receptor, interleukin 2 and neopterin in diffuse and limited scleroderma: effects of chlorambucil.

In a study of 48 patients with systemic sclerosis (SSc). elevated serum levels of soluble interleukin 2 receptor (IL-2R), interleukin 2 (IL-2) and neopterin (indicators of lymphocyte/monocyte activation) were noted in 100, 44 and 40% of early untreated patients with SSc (11 diffuse, 5 Limited). Levels of IL-2R, but not IL-2 or neopterin, were lower in patients with longer duration of disease and possibly with chlorambucil therapy. Pharmacologic alterations of markers of humoral or cell mediated immunity may not be an accurate reflection of clinical efficacy of chlorambucil.

Adult↗
PubMed1990

Prevention of hypogammaglobulinemia of prematurity with intravenous immune globulin.

We evaluated the effect of 1 g/kg intravenous immune globulin (IGIV) on immunoglobulin levels and half-life, the dose and frequency of IGIV administration necessary to maintain IgG levels at greater than 400 mg/dL, and IGIV effect on immunoglobulin levels after discharge in infants less than or equal to 32 weeks' gestation and less than or equal to 1500 g. Fifteen infants received 31 infusions at IgG levels less than or equal to 400 mg/dL. Immunoglobulin levels were obtained 24 hours postinfusion, weekly during hospitalization, and monthly after discharge. Mean IgG postinfusion was 980 mg/dL. Mean IgG half-life was 18 days (range 7 to 41). Smaller infants with greater than or equal to 5% of blood volume removed per week experienced shorter immunoglobulin half-lives. IGIV caused increased IgG levels after discharge and did not delay endogenous production of IgG. We conclude that 1 g/kg IGIV given to infants less than or equal to 32 weeks' gestation and less than or equal to 1500 g every 1 to 6 weeks during hospitalization, depending on weight and blood volume removed, prevents hypogammaglobulinemia of prematurity.

Dysgammaglobulinemia↗
PubMed1989

Dot-ELISA for serodiagnosis of human infections due to Western equine encephalitis virus.

A standard dot-ELISA (enzyme-linked immunosorbent assay) was modified for use in detecting IgM and IgG class antibodies to Western equine encephalitis (WEE) virus in serum samples from humans infected with this virus. Nitrocellulose membranes were soaked in supernatant fluid from WEE virus-infected cell cultures, air dried, and blocked with bovine protein. Serum samples were pipetted onto sections of the nitrocellulose, incubated, and washed. Addition of antibody to human immunoglobulin conjugated to alkaline phosphatase and enzyme substrate were used to detect the antibodies. Of 13 samples positive for IgM antibody to WEE virus by IgM antibody capture ELISA, 12 were positive by IgM dot-ELISA. IgG antibody to WEE virus was detected by dot-ELISA in 7/8, 10/14 and 7/10 samples with neutralizing, hemagglutination-inhibiting, or complement-fixing antibodies, respectively.

Animals↗
PubMed1989

Dual parameter analysis of myeloma cells by flow cytometry. DNA content of cells containing monotypic cytoplasmic immunoglobulin.

Dual-parameter flow cytometric analysis of monotypic cytoplasmic immunoglobulin (CIg) and DNA content on 15 myeloma marrows allowed S-phase determination of the CIg(+) tumor separately from the CIg(-) hematopoietic cell pool. The median percentage of the CIg(+) cells in S-phase was 2% compared with 5% for the CIg(-) cells. The median survival of patients with more than 2%, and those with 2% or less CIg(+) S-phase cells was 2 months and more than 13 months, respectively, from the time of study. Ploidy analysis identified four patterns of plasma cell DNA content: entirely hyperdiploid, entirely diploid, combined diploid and tetraploid stemlines, and tumors containing diploid and aneuploid CIg(+) cells. A monotypic CIg(+) double stemline myeloma was distinguished from two aneuploid tumors containing admixed normal, diploid polyclonal plasma cells. This technique provides an improved and expedient means for determining the proliferating fractions of myeloma cells and enhances recognition of double stemline tumors and clonal evolution in myeloma.

Cytoplasm↗
PubMed1988

Urinary phenylacetate and response to methylphenidate.

Phenylacetate (PAA) is the metabolic end-product of phenylalanine, a catecholamine precursor, and of phenylethylamine, a centrally active neurochemical substance which has been implicated in the actions of stimulant medications. PAA has been reported to be low in unipolar depression. We measured 24-h urinary PAA in normal controls (N = 21) and in-patients with unipolar depression (N = 33; 12 drug-free) and did subsequent dexamethasome suppression tests (DST). We also gave patients methylphenidate challenges, examining mood response. There were no significant differences between depressed patients and controls in 24-h urinary PAA excretion (P greater than 0.9). However, the variance in PAA excretion was higher in patients than normals and 5 patients had values at or above the 99% confidence limits for the normal control group. There was no association of DST results with PAA excretion (P greater than 0.4). Patients with a worsened mood after taking methylphenidate excreted less PAA than those with an improved mood, however (P less than 0.025). The clinical and theoretical significance of these results is discussed.

Adult↗
PubMed1988

Clinical significance of a single test for anti-cardiolipin antibodies in patients with systemic lupus erythematosus.

PURPOSE: Clinicians have difficulty interpreting results of tests for anti-cardiolipin antibodies (aCL) because of conflicting reports of the clinical associations of these antibodies in patients with systemic lupus erythematosus (SLE). We therefore decided to evaluate the clinical associations of aCL in an effort to facilitate interpretation of single reports of either positive or negative test results. We also assessed the role of estrogen on the development of aCL. PATIENTS AND METHODS: The study population consisted of 85 consecutive outpatients with SLE and 40 control subjects. Serum samples and clinical and laboratory data were obtained from each patient and control. Testing for aCL was performed using a standardized enzyme-linked immunoabsorbent assay developed at an international workshop. RESULTS: The presence of aCL was documented in 42.4 percent of patients with SLE and 7.5 percent of control subjects. In patients with SLE, these antibodies were significantly associated with thrombosis, fetal loss, and thrombocytopenia, but not with other manifestations. Measurement of all isotypes optimized clinical correlations. Titers did not add clinical utility. Fluctuations of levels of aCL occurred, making it difficult to interpret a single negative result. Among control subjects, the presence of aCL was not significantly more common in women who used oral contraceptives. CONCLUSION: Our findings suggest that positive results of testing for aCL correlate with a predisposition for thrombosis, fetal loss, and thrombocytopenia in patients with SLE; however, the test is not predictive for other clinical manifestations of SLE, including activity and severity of disease. We believe that measurement of all isotypes of aCL should be performed in patients with SLE considering pregnancy, to identify those with a high risk of fetal loss, and in SLE patients with a thrombotic episode.

Adult↗
PubMed1988

Comparison and standardization of measurement of anti-acetylcholine receptor antibody between laboratories.

The presence of autoantibodies to the acetylcholine receptor (anti-AChR) is useful in the diagnosis of myasthenia gravis, and their titre correlates with severity of the disease. Standardization of their measurement is therefore clinically important. Six laboratories world-wide were asked to determine anti-AChR under local conditions in coded samples and to repeat the measurement on the same samples recorded. There was a high degree of consensus over rank order of the samples but a wide systematic variation in the titres obtained. Standardization of units is an important next step in improving the comparability of anti-AChR data between laboratories.

Autoantibodies↗