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At least 19 recordsLinked to original sources
PubMed1978

Isolation of tuberculin peptides from tuberculin purified protein derivative (PPD).

Tuberculin purified protein derivative (PPD) obtained from the filtrate of Mycobacterium tuberculosis was hydrolysed with proteinase, trypsin, or chymotrypsin. Each hydrolysate consisted of a tuberculin peptides mixture (TPM). From each TPM 16 fractions were obtained by ion-exchange chromatography on Dowex 50W-X8 but only one fraction was isolated from each of the 16 fractions which showed tuberculin activity in guinea pigs sensitized with M. bovis (bcg) or M. tuberculosis. This fraction was designated "purified tuberculin peptide" (PTP). The PTP fraction from the proteinase hydrolysate (PTP-proteinase) was rechromatographed on Dowex 1-X2 and two tuberculin peptide fractions having molecular weights of 3200 and 12,000 were isolated. The potency of these two fractions was assessed in guinea pigs sensitized with M. bovis (BCG) and with M. tuberculosis and they were approximately 4 to 7 times more potent than either the international standaCG and of at least equal potency to either PPD-S or Connaught PPD in guinea pigs sensitized with either M. kansasii, M. scrofulaceum, M. intracellulare, or M. avium whereas very little if any cross-reactivity was elicited by these two fractions. This lack of response indicates that either fraction could be used as an aid to differentiate between sensitization due to M. tuberculosis or M. bovis and sensitization attributed to other mycobacteria.

Animals↗
PubMed1975

Suppression of tuberculin skin reactivity by prior tuberculin skin testing.

In two consecutive studies, eighteen and forty-one normal subjects were given a standard tuberculin skin test of 1 tuberculin unit (0.02 mug of PPD). Two days later another skin test was given. Readings of the skin reactions showed that subjects exhibiting strongly positive skin reactions in their primary skin tests showed a significantly smaller indurations in their primary skin tests tended to have equal or larger areas of induration after the secondary skin tests. These observations are discussed in relation to the possible existence of regulatory mechanisms of cell-mediated immune reactions.

Adult↗
PubMed1975

Adoptive transfer of cell-mediated immunity to tuberculin using RNA from tuberculin-sensitive subjects.

Adoptive transfer of delayed hypersensitivity skin test response to tuberculin with 'immune' RNA extracted from the sensitized lymphocytes of a healthy subject or a patient with Hodgkin's disease was successfully demonstrated in previously non-sensitive patients with neoplastic diseases including Hodgkin's disease. 'Non-immune' RNA obtained from non-sensitive man, on the other hand, failed to transfer PPD skin reactivity in non-sensitive recipients. 'Immune' RNA-mediated PPD skin test response remained positive for a considerable period of time, indicating that the effect of 'immune' RNA is systemically active. 'Immune' RNA was found to be RNase-sensitive but DNase-resistant. In vitro adoptive transfer of delayed hypersensitivity with 'immune' RNA, as assayed by lymphocyte transformation test, was unsuccessful.

Deoxyribonucleases↗
PubMed1978

Comparison of the tine and Mantoux tuberculin tests. Report of the Tuberculin Subcommittee of the Researched Committee of the British Thoracic Association.

Intracutaneous (Mantoux 5 TU) and tine tuberculin tests were performed on the opposite arms of 307 people. The results of each test were read by two independent observers at either 48 or 72 hours. Positive readings were recorded in 59% of the Mantoux tests; induration was 10 mm or more in 34.7% of cases. Positive readings were recorded for 3.9% of the tine tests, and a further 15.5% were recorded in the doubtful category. The tine test is unsuitable for epidemiological use because of the high proportion of negative and doubtful results in people positive on the Mantoux test. For the same reasons its usefulness in clinical practice is very limited.

False Negative Reactions↗
PubMed1975

The multi-facets of tuberculin standardization.

Some parameters affecting the standardization of a tuberculin preparation have been evaluated and it has been shown that: 1) The loss of tuberculoprotein on the surfaces of containers is in the order of 0.15 mug/cm2 and the 0.18 mug/cm-2 for glass and plastic surfaces respectively, and that this loss can be prevented by the addition of a nonionic anti-adsorption agent such as Tween 80. 2) For non-stabilized tuberculin PPD solutions the losses of PPD due to adsorption increased linearly with the Surface to Volume ration. 3) Exposure to light had a deleterious effect on tuberculin PPD decreasing its biological potency and altering its appearance. This effect increased with the dilution of the tuberculoprotein solution, and can be prevented by storing the tuberculin in amber containers. 4) The potency of tuberculoprotein was dependent on its molecular weight, and the % distribution of tuberculoprotein molecules of different molecular weight varied from batch to batch. This variation can be eliminated by preparing a large batch of tuberculin in a dried form sufficient to fill the demand for many years to come. 5) The route of injection and the species or strains of mycobacteria used for sensitization of guinea pigs affected the relative potency of a tuberculin preparation. 6) The size of a tuberculin skin reaction increased as the volume of tuberculin injected intracutaneously into sensitized guinea pigs was increased although the number of tuberculin units administered was the same. 7) The sizes of skin reactions to certain doses of tuberculin was affected by other doses of tuberculin being injected simultaneously at other sites. 8) Sex and age of guinea pigs affected the size of the tuberculin skin reaction. 9) The genetic make-up of the test animals affected the relative potency of a given tuberculin preparation. 10) Racial differences among various populations might account for different levels of tuberculin reactivity to a given tuberculin preparation. It is hoped that this work has made us aware of the many problems which can be encountered in standardizing tuberculin and it is also to be hoped that the solutions we have offered to some of these problems can be useful to those attempting to standardize allergens other than tuberculin.

Animals↗
PubMed1979

Tuberculin test conversion during repeated skin testing, associated with sensitivity to nontuberculous mycobacteria.

To determine whether repeating the tuberculin test after a brief interval might result in tuberculin conversion, we tested 213 healthy volunteers twice, 1 month apart, with 5 TU of tuberculin purified protein derivative (PPD). Three nontuberculous mycobacterial antigens (PPD-G, PPD-Y, and PPD-B) were also applied with the first tuberculin test. By widely used criteria, 14 volunteers (6.6 per cent) converted their tuberculin tests from negative to positive on the second testing. Whereas 13 of 103 subjects (12.6 per cent) with nontuberculous antigen sensitivity converted their tuberculin test to positive, only one of 110 subjects (0.9 per cent) with no known prior mycobacterial sensitivity converted to positive (P less than 0.005; x2 = 10.05). When retested with 5 TU of tuberculin PPD 6.5 months after the second test, nine of 13 converters reverted to negative. We conclude that tuberculin conversion may occur when the skin test is repeated at 1 month, and that boosting of cross-reacting mycobacterial sensitivity might have caused a portion of the conversions in this population of young, healthy midwestern volunteers. Sensitivity to Mycobacterium tuberculosis might also be boosted by tuberculin testing. Because the prevalence of sensitization by tuberculous and nontuberculous mycobacteria can be expected to vary in different populations, the significance of tuberculin conversion will also vary with the population being tested.

Adolescent↗
PubMed1992

Sensitivity to PPD tuberculin and M. scrofulaceum sensitin in schoolchildren BCG vaccinated at birth.

OBJECTIVE: To determine the degree of and variation in sensitivity to PPD RT 23 tuberculin and M. scrofulaceum sensitin RS 95 at school age in children BCG vaccinated at birth. DESIGN: Double-testing by applying standard WHO Mantoux tests and inspecting BCG scars. SETTING AND PARTICIPANTS: Urban and rural schools in Southwest Finland, 1091 children aged 11-13 years. MAIN OUTCOME MEASURES: Size of tuberculin and sensitin indurations and BCG scar (mm). RESULTS: The mean size of tuberculin indurations was 7.2 mm, sensitin indurations 8.1 mm and BCG scars 7.9 mm. The reaction to sensitin was significantly larger than to tuberculin (95% confidence interval 0.58-1.10 mm) and the zero reactions to sensitin were fewer. Correlation between tuberculin and sensitin indurations was significant (r = 0.75, 95% confidence interval 0.72-0.77). There were induration greater than or equal to 15 mm to tuberculin in 16% and to sensitin in 14%. Sensitin indurations exceeded those of tuberculin by 4 mm or more in 14% of the children with at least 5 mm tuberculin indurations. CONCLUSIONS: High tuberculin sensitivity in healthy schoolchildren may be partially maintained by contact with environmental mycobacteria. Our data do not prove but very probably indicate that children have protective immunity. In view of the current incidence of tuberculosis in Finland and the likelihood that lymph node infections and sensitivity to environmental mycobacteria will increase, continued BCG vaccination at birth is recommended.

Adolescent↗
PubMed1975

Comparison of the specificty of human and bovine tuberculin PPD for testing cattle. 1--Republic of Ireland.

A tuberculin testing trial in cattle was carried out in the Republic of Ireland to compare the specificity for bovine tuberculosis of a human purified protein derivative (PPD) tuberculin (Weybridge) with that of a bovine PPD (Rotterdam), and to determine whether discrimination between specific and non-specific reactions to mammalian tuberculin is better with doses of tuberculins smaller than those traditonally used for testing cattle. Tests were carried out in 510 cattle, 395 of which were shown by post mortem examination to be tuberculous and 115 non-tuberculous. Three dilutions at five-fold intervals of both mammalian tuberculins were used together with two dose levels of avian tuberculin PPD (Weybridge), and all reactions were measured both by increase in skin fold thickness and by diameter of induration. In the environment of this trial, the bovine PPD was shown to be more specific for bovine tuberculosis than the human PPD, and particularly in differentiating from "skin tuberculosis". There was no indication of greater specificity at lower doses of tuberculin. Measurement of induration diameter proved a satisfactory alternative method of reading tuberculin reactions in cattle under field conditions.

Animals↗