Guillain-Barré syndrome associated with Campylobacter infection.
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Campylobacter Infections↗
Biomedical subjects
J Kaldor
Publications and source records attributed to J Kaldor.
Guillain-Barré syndrome and Campylobacter jejuni: a serological study.
The association between Campylobacter jejuni infection and Guillain-Barré syndrome was investigated serologically in a retrospective study of 56 patients admitted to this hospital over four years. Evidence of preceding C jejuni infection was found in 21 (38%) of these patients, indicating that C jejuni was the most common single identifiable pathogen precipitating the disease. Among those patients who had presented with preceding diarrhoea the serum antibody response was similar to that in uncomplicated C jejuni enteritis. Patients with serological evidence of preceding C jejuni infection manifested a significantly more severe form of the disease. In cerebrospinal fluid the predominant specific antibody class was IgG, and this was closely related to the serum titres of specific IgG. IgA and IgM specific antibodies were found only in the cerebrospinal fluid of patients with recent C jejuni infection. These findings support the possibility that humoral immune factors are responsible for the neural damage and demyelination seen in Guillain-Barré syndrome.
Antibodies, Bacterial↗
An evaluation of Salmonella (Ames) test data in the published literature: application of statistical procedures and analysis of mutagenic potency.
We searched the published literature for Salmonella test data on some 450 chemicals. Only 137 of more than 400 articles containing original data satisfied minimum criteria for a quantitative analysis [1751 experiments, comprising data on 152 chemicals (Table 1)]. Many of these papers did not report basic information about the test protocol (Table 2). We used previously described statistical procedures (Bernstein et al., 1982) to estimate the initial slopes of the dose-response curves and corresponding standard errors. We also applied tests for significance and linear goodness-of-fit. We then used the results of these analyses to examine several issues: (1) Linearity of the low dose region of the dose-response curve. We found that the overwhelming majority of curves were linear, though ability to detect non-linearity of dose-response curves in the standard plate test is only limited. 7% of all experiments to which the goodness-of-fit test was applied were curves of increasing slope, and with a few possible exceptions, these were not obviously associated with any particular mutagens, even those generally considered to produce non-linear effects such as MNNG and EMS (Table 3). (2) Performance of the statistical test for significance. Results of the statistical test for significance of the dose-response were compared with author's opinions as to positivity. In almost all cases (94%) results of the statistical test and authors opinions were the same. In the examples of conflicting opinions, the reasons were: (a) the statistical test places more weight than do most authors on the presence of a linear dose-response; (b) most authors tend to require at least a 2-fold increase over the spontaneous background for 'significance', and (c) when the number of spontaneous revertants is small (e.g., TA1537), authors tend to require a larger increase in induced revertants than when the spontaneous background is large, whereas the statistical procedure makes no such distinction. These factors result in the statistical test tending to identify more experiments as positive than do authors, provided there is a linear dose-response, and authors tending to judge more experiments as positive when the dose-response is not linear. (3) Reproducibility. Among the 1751 experiments there were 122 data-sets (a total of 333 experiments) in which the same chemical was tested by two or more different laboratories under the same protocol. 21 of the 122 data-sets had some disagreement between experiments as to whether results were positive or negative (Table 4).(ABSTRACT TRUNCATED AT 400 WORDS)
Dose-Response Relationship, Drug↗
Guillain-Barré syndrome associated with Campylobacter jejuni enteritis.
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Adolescent↗
Statistical association between cancer incidence and major-cause mortality, and estimated residential exposure to air emissions from petroleum and chemical plants.
An ecologic study design was used to investigate the relationship between exposure to air emissions produced by the petroleum and chemical industries, and average annual cancer incidence and major cause mortality rates among whites in Contra Costa County, California. Estimates for the exposure to major industrial sources of sulfur dioxide, hydrocarbons and oxides of nitrogen were used to subdivide the county by level of exposure to petroleum refinery and chemical plant emissions. Cancer incidence and major cause mortality rates were then calculated for whites in each of the exposure areas. In both males and females, residential exposure to petroleum and chemical air emissions was associated with an increased incidence of cancer of the buccal cavity and pharynx. In males, age-adjusted incidence rates for cancers of the stomach, lung, prostate and kidney and urinary organs were also associated with petroleum and chemical plant air emission exposures. In both sexes, we found a strong positive association between degree of residential exposure and death rates from cardiovascular disease and cancer, and a less strong positive association between exposure and death rates from cerebrovascular disease. There was also a positive association in men for deaths from cirrhosis of the liver. Although these observed associations occurred across areas of similar socioeconomic and broad occupational class, confounding variables and the "ecologic fallacy" must be considered as possible explanations. In particular, the stronger findings in men suggest an occupational explanation of the cancer incidence trends, and the effect observed in cirrhosis mortality suggests that lifestyle variables such as alcohol consumption were not adequately controlled for. While the public health implications of our findings remain unclear, the evidence presented is sufficient to warrant follow-up studies based on individual data in which possible biases can be more readily controlled.
Air Pollutants↗
Characterization of a precipitating antigen detected in the serum of patients with viral hepatitis.
During a search for the aetiological agent of non-A non-B hepatitis, a precipitating antigen was detected in the sera of some patients during the acute phase of their illness. The antigen was detected by agar gel diffusion using antibody from convalescent sera obtained from patients with non-A non-B hepatitis, and from haemophiliac sera. The antigen was usually detected early in the patient's illness, disappearing as liver function tests returned to normal. In some patients specific antibody appeared during the convalescent phase of the disease. The antigen does not appear to be specific for non-A non-B hepatitis, as it could be detected with similar frequency in patients with hepatitis A or hepatitis B and some patients with other liver disorders. Biochemical and biophysical studies suggest that the antigen is probably an abnormal lipoprotein produced as a result of acute liver damage.
Antigens↗
A comparison of alternative measures of mutagenic potency in the Salmonella (Ames) test.
Both the spontaneous and the induced mutation rates in Salmonella tester strains vary among different laboratories, and also within the same laboratory over time. If there is an association between spontaneous and induced mutagenesis, a measure of mutagenic potency that incorporates the background may be more consistent than the simple measure of the induced slope. We have used the statistical procedures recently described by Bernstein et al. (1982), and a large data-base of Salmonella test results to examine the association between spontaneous and induced mutation and to compare several alternative measures of mutagenic potency. A correlation analysis indicated an association between spontaneous and induced mutation for TA98, TA1537 and TA1535; TA1538 was close to being significant. This was observed over a wide range of chemicals. In addition, for TA98, for which we observed the strongest association, we obtained a rough estimate of the relationship between slope and intercept by using least squares to fit K and p in the power curve beta = k alpha p. We then chose 3 simple potency measures: the slope, the ratio of slope to spontaneous background, and the ratio of slope to the square-root of spontaneous background. These corresponded to the range of p's estimated from the least-squares fit procedure. The reproducibility of these measures was compared and no significant differences were found. Though there were some differences in the relative potency ranking of chemicals using the different measures, they were highly correlated.
Mutagenicity Tests↗
Serum antibodies in Campylobacter enteritis.
A solid-phase enzyme immunoassay method for the measurement of total and class-specific serum antibodies to Campylobacter jejuni was developed. The test was found to be both sensitive and specific. Immunoglobulin M, G, and A antibodies were detected in about 90% of sera collected from patients recovering from Campylobacter enteritis, with the pattern of appearance and decline of these antibodies conforming to that usually seen in an acute infection. A poor antibody response was noted in patients with intermittent or prolonged enteritis. The clinical implications and diagnostic value of this test are discussed.
Antibodies, Bacterial↗
An empirical approach to the statistical analysis of mutagenesis data from the Salmonella test.
A number of recent papers have suggested basing the statistical analysis of Salmonella (Ames) mutagenicity test results on a mathematical model of the complete dose-response curve. For most mutagens at low doses the curve increases linearly; then, as the dose increases, the curve may flatten and finally turn downwards due primarily to effects of toxicity. The exact mechanism underlying this shape is, however, not well understood and is likely to vary for different chemicals. A different approach is to assume that the initial part of the curve is linear and to base the statistical analysis solely on this region, reasoning that it contains most of the interpretable information about the mutagenesis dose response. In this paper a formal method of deciding which points are on the initial linear part of the curve is described, and a statistical method is proposed for analyzing these points. Computer simulations are used to examine the properties of the procedure and comparisons are made with a previously proposed mathematical model of the whole curve. It is concluded that the method suggested here provides a very satisfactory, robust method for the standard analysis of Salmonella data.
Dose-Response Relationship, Drug↗
Serum immunoglobulin levels in acute A, B, and non-A, non-B hepatitis.
Immunoglobulin M, G, and A concentrations were determined by radial immunodiffusion in sera collected from 117 patients with acute hepatitis A, hepatitis B, or non-A, non-B hepatitis. Statistically significant differences in IgG and IgM levels were detected between the three groups. In particular, elevated IgG and almost-normal IgM levels were regularly detected in patients with non-A, non-B hepatitis while the opposite pattern was seen in patients with hepatitis A. Calculation of a serum IgG/IgM ratio enabled discrimination between most patients with non-B hepatitis. In 92% of patients with hepatitis A, the ratio was less than 6, whereas 82% of patients with non-A, non-B hepatitis had ratios of greater than 6. The IgG/IgM ratio may be of value in distinguishing between subjects with the two forms of the disease when specific serologic tests are unavailable.
Hepatitis C↗
Immunoglobulins in the cerebrospinal fluid of patients with Guillain-Barré syndrome.
Increased immunoglobulin levels in the cerebrospinal fluid of patients with Guillain-Barré syndrome were found in association with increased protein levels. Evaluation of the immunoglobulin/protein ratios led us to conclude that the increase in immunoglobulin levels may be due to a leakage of plasma proteins and is unlikely to be caused by a local immune response to a preceding antigenic stimulus.
Blood-Brain Barrier↗
The incidence of liver specific antigens in liver disease.
Three soluble, liver-specific antigens were demonstrated in the sera of between 20 and 40% of patients suffering from liver related diseases; the pattern of distribution of these antigens in patients suffering from hepatitis A, hepatitis B, non-A non-B hepatitis and from glandular fever is described. Liver-specific antigens were also detected in approximately 10% of patients in whom no primary liver abnormality ws suspected but not in a control group of healthy individuals. Our results suggest that the appearance of liver antigens in the sera of patients suffering from specific diseases associated with abnormalities of liver function is inconstant and hence of no clinical value.
Antigens↗
Ozone toxicity symptoms among flight attendants.
Because of persistent complaints of ozone-toxicity type symptoms among crew members of commercial airlines, we undertook a survey to determine the extent of the problem and the associated flight factors. Self-reported questionnaires and flight diaries were completed by 1,330 flight attendants, (FAs) working for three different airlines. Ozone-toxicity type symptoms were reported three or four times more frequently by FAs with airlines flying at high altitudes than by those with low-flying airlines. When examined by characteristics of flights, the ozone-toxicity type symptoms were significantly associated with flight altitude, duration and type of aircraft, but not with years worked, sex, medical history, or home residence. Other symptoms indicative of fatigue or stress were mainly associated with flight duration. While these indirect data cannot implicate ozone specifically, they offer evidence that ozone-related health problems do exist among a large proportion of FAs.
Adult↗
Coproantibodies in hepatitis A: detection by enzyme-linked immunosorbent assay and immune electron microscopy.
A collection of 104-fecal specimens from 45 patients with hepatitis A, 14 patients with hepatitis B, 10 patients with non-A, non-B hepatitis, 6 patients with diseases other than hepatitis, and 18 healthy adults were studied for the presence of secretory immunoglobulin A and immunoglobulin M to hepatitis A virus by solid-phase enzyme-linked immunosorbent assay and immune electron microsopy. Specific fecal antibody was found only in patients with hepatitis A. Of 54 specimens from patients with hepatitis A, only 10 (18.5%) possessed detectable levels of fecal antibody, and each of these was collected within 10 days from the onset of dark urine. All 10 fecal specimens contained hepatitis A-specific secretory immunoglobulin A, and 4 were also positive for hepatitis A-specific immunoblobulin M. Four of the 10 antibody-positive specimens also contained hepatitis A virus particles which could be shown by immune electron microscopy to be coated with specific secretory immunoglobulin A. Since specific fecal antibody was not detected in all the patients with hepatitis A that were studied, it would appear to have limited diagnostic value, although its detection is evidence of recent infection.
Antibodies, Viral↗
Value of latex test in cryptococcal meningitis.
The history of a man suffering from chronic cryptococcal meningitis is presented. A series of cerebrospinal fluid and serum specimens from this patient were investigated retrospectively by latex agglutination for the presence of cryptococcal antigens. The results were related to other laboratory findings, and to the patient's clinical progress. The cryptococcal latex agglutination test was shown to be potentially useful in the diagnosis, management, and prognosis of such patients.
Adult↗
Solid-phase enzyme-linked immunosorbent assay for detection of hepatitis A-specific immunoglobulin M.
A solid-phase enzyme linked immunosorbent assay was developed for the detection of immunoglobulin M antibody to hepatitis A virus. The system was capable of detecting hepatitis A-specific immunoglobulin M in a single dilution of serum and appears to be a reliable and rapid means of establishing a diagnosis of hepatitis A infection. Specific immunoglobulin M was only detected in patients with serologically confirmed hepatitis A and not in patients with other forms of hepatitis, chronic liver disease, or autoimmune disease. In patients with hepatitis A, specific immunoglobulin M was usually detectable for 6 weeks after the onset of dark urine, and the longest period for which it was present in any patient was 115 days. This enzyme-linked immunosorbent assay is rapid, simple to perform, and does not require complicated equipment. Provided adequate supplies of purified reagents can be obtained, this enzyme-linked immunosorbent assay procedure is likely to simplify hepatitis A serology, because the same antibody-coated plates can be utilized to detect hepatitis A virus, anti-hepatitis A virus, and hepatitis A-specific immunoglobulin M.
Antibodies, Viral↗
Haemophilus influenzae type b antigenuria in children.
Detection of Haemophilus influenzae type b (HIb) antigenuria by latex agglutination has been shown to be sensitive, specific, and rapid. In children, antigenuria persisted for a mean duration of 10 days and a maximum of 18 days. Antigenuria was demonstrated in 25 of 30 patients with HIb infection but not in 62 with other types of infection. In five children, antigenuria confirmed the diagnosis in the absence of bacteriological confirmation. In five other children, antigenuria was not found, but in this group the antigen was detected in another body fluid or HIb was recovered.
Adolescent↗
Latex agglutination in diagnosis of bacterial infections, with special reference to patients with meningitis and septicemia.
Antibody-sensitized latex particles were used to demonstrate specific bacterial antigens in cerebrospinal fluid, blood and urine. Difficulties with reported nonspecific agglutinations appear to have been overcome. The method seems to be sensitive, specific, and simple to perform, and shows a better detection rate than culture or countercurrent immunoelectrophoresis. Urinary excretion of Haemophilus influenzae antigens was followed. The diagnostic usefulness of demonstrating such antigens at a later stage of disease is discussed.
Antigens, Bacterial↗