Percentage Of Positive Reactions Research Articles

Effects of Impacted Third Molars Extraction on Periodontal Status of Second Molar and Oral Health-Related Quality of Life

Objective: The study investigated the impacts of third molar (M3) extraction on periodontal status of adjacent second molar (M2) and oral health-related Quality of life (QoL). Methods: 272 cases with M3 were randomly divided into treatment group and control group, each of 136 cases. Questionnaire survey evaluated demographic features of the subjects. Gingival index (GI), plaque index (PLI) and conscious symptoms of adjacent teeth of the M3 were detected in both groups at baseline (T0), 1 week (T1), 1 month (T2) and 6 months (T3) after treatment. The impacts of QoL were evaluated using OHIP-14 to measure total scores and various items of OHIP-14 at different observation point. Results: The percentage of swelling and toothache in the treatment group was significantly lower than that in the control group at T1, T2 and T3. Significant differences could be seen in GI and PLI between the treatment and control groups at T2 and T3. The total score of OHIP-14 in T2 and T3 was significantly lower than that in T0 and T1 in the treatment group. The 14 items scores and the percentage of positive reaction in the treatment group were significantly lower than those in the control group at T2 and T3. Conclusion: M3 extraction had significant impacts on the periodontal status of the second molar and quality of life. This study would provide an important basis for the prophylactic removal of M3 in clinical work.

Patch testing in drug reaction with eosinophilia and systemic symptoms (DRESS): A literature review.

The literature on positive patch test results in drug reaction with eosinophilia and systemic symptoms (DRESS) is reviewed. One hundred and five drugs were identified that have together caused 536 positive patch tests in 437 DRESS patients. By far, the most reactions (n=145) were caused by carbamazepine, followed by amoxicillin, isoniazid, phenytoin, ethambutol, fluindione, phenobarbital, rifampicin, and ceftriaxone; 43 drugs each caused a single case only. The drug classes causing the highest number of reactions were anticonvulsants (39%), beta-lactam antibiotics (20%), antituberculosis agents (11%), non-beta-lactam antibiotics (6%), and iodinated contrast media (5%). The sensitivity of patch testing (percentage of positive reactions) is high for anticonvulsants (notably carbamazepine), beta-lactam antibiotics (notably amoxicillin), and, possibly, iodinated contrast media. Allopurinol and sulfasalazine frequently cause DRESS but never give positive patch tests. Patch testing in DRESS appears to be safe, although mild recurrence of DRESS symptoms, mostly skin reactions, may not be rare. Multiple drug hypersensitivity was found to occur in 16% of all patients, but it is argued that the true frequency is higher. Clinical aspects of DRESS, including diagnosing the disease and identifying culprit drugs (patch tests, intradermal tests, in vitro tests, challenge tests) are also provided, emphasizing the role of patch testing.

Results of patch testing in acute generalized exanthematous pustulosis (AGEP): A literature review.

The literature on positive patch-test results in acute generalized exanthematous pustulosis (AGEP) is reviewed. Ninety-three drugs were identified that have together caused 259 positive patch tests in 248 patients with AGEP. The drug classes causing the highest number of reactions are beta-lactam antibiotics (25.9%), other antibiotics (20.8%), iodinated contrast media (7.3%), and corticosteroids (5.4%), together accounting for nearly 60% of all reactions. The highest number of reactions to individual drugs was to amoxicillin (n=36), followed by pristinamycin (n=25), diltiazem (n=14), amoxicillin-clavulanic acid (n=13), clindamycin (n=11), and iomeprol (n=8); 59 of the 93 drugs each caused a single case only. The "Top-10" drugs together caused over 50% of all reactions. The sensitivity of patch testing (percentage of positive reactions) in patients with AGEP is largely unknown, but may generally be ~50%, which also applies to pristinamycin. Patch testing in AGEP appears to be safe, although mild recurrence of AGEP skin symptoms or other rashes may occur occasionally. Clinical aspects of AGEP, including epidemiology, etiology and pathophysiology, clinical features, histology, treatment, and prognosis are briefly presented, as are diagnosing the disease and identifying the culprit drugs with patch tests, intradermal tests, in vitro tests, and challenge tests.

Sensitization to inhaled and food allergens in children

A retrospective analysis of the annual allergen sensitization detected during skin testing in children aged 3-17 years was performed. Significant positive data were more frequently (p 0.01) detected after testing for indoor (70.2%), food (72.7%) and pollen allergens (67.9%) compared to epidermal allergens (58.6%). Sensitization to house dust (43.6%) and library dust (25.7%), guinea pig hair (22.6%), cat hair (21.8%), horse dandruff (19.6%), sheep wool (16.8%), as well as pollen of trees (82.4%), meadow grasses (64.0%) and weeds (64.1%) was most common in group of inhaled allergens. Skin testing in the group of food allergens revealed that children were more sensitized to chicken eggs, fish, milk, chicken and wheat. Among food cereals, peak percentage of positive reactions was observed for wheat (9.9%) and barley groats (9.1%) compared to oatmeal (4.4%), rye flour (5.0%) and buckwheat (5.6%). While assessing the data in all allergen groups it was found that low positive reaction with 2-3 mm blister in diameter was most common. The frequency of detected positive data for all allergen groups varied markedly on different calendar months and also depended on allergen preparation batch. Intensity of reactions did not significantly differ in children with allergic diseases vs. those at risk of developing allergopathology.

Physiological and Pathological Alterations in the Mammary Gland of Holstein Cows during Transition Period

Background: Physiological and immunological adaptations occurred in peripartum period may be responsible for susceptibility to intramammary infections during colostrogenesis. Increase in blood flow and hormones cause physiological edema by accumulation of lymphatic fluid in interstitial space. Specific composition of mammary secretion increases the susceptibility to mastitis. So, the study of physical, cellular and microbiological changes in the mammary gland in this period are fundamental for understanding, diagnosing and adopting prophylactic measures for bovine mastitis. This study aimed to characterize physiological and pathological changes that occur in the mammary gland during transition period.Materials, Methods & Results: Thirteen cows, in second to fourth lactation were followed from 3 weeks pre-calving to 3 weeks post-calving. Cows were submitted weekly to physical examination of mammary gland, strip cup test, California Mastitis Test (CMT), Microscopic Somatic Cell Count (MSCC), and bacteriological examination of mammary secretion. Mammary quarters were divided into two groups: BAC-: samples that did not present bacteriological growth throughout transition period; BAC+: samples that presented bacteriological growth in at least two isolates of the same bacterial genus. Regarding physical examination of mammary gland, the parameters localized or generalized alteration in volume, asymmetry, reddish color, reduced skin elasticity, increased temperature, and swollen consistency presented higher frequencies in the BAC- group. On the other hand, infection in mammary quarters of cows from BAC+ group promoted a decrease in frequencies of increased volume, decreased elasticity, and elevated temperature in the mammary gland, in addition to a higher positivity to CMT and higher cellularity. Overall rate of intramammary infection was 25.82%, with non-aureus Staphylococci (NAS) being the predominant agent (69.2%). Maximum peak of bacterial isolates occurred immediately after calving (33.3%). Differences were observed between groups (P = 0.021) for CMT, showing a higher frequency of positive tests in BAC+ group (36.5%) compared to BAC- group (18%). MSCC varied between weeks (P = 0.001), groups (P = 0.001), and between the interaction of the two variables (P = 0.019). Highest median value of MSCC was observed at calving (1.5 × 106 cells/mL), being different (P = 0.001) from the +1, +2, and +3 weeks and the lowest median value of MSCC (0.08×106 cells/mL) was observed in +3 compared to previous weeks (P < 0.05).Discussion: NAS was predominantly isolated in mammary secretions of cows during peripartum, it is commonly found in the skin and canal of the teat and are associated with subclinical mastitis. Peak of mammary infection was observed on calving, probably by the cortisol peak resulting in a stress leucogram and decrease in the functional activity of immune cells. Changes observed in the physical examination of mammary gland of cows from BAC- group are compatible with physiological edema caused by circulatory changes that occurs with the proximity of calving, increasing blood flow necessary for production of colostrum. Alterations in the mammary quarters of cows from BAC+ group may be associated with functional loss of mammary parenchyma or persistent infectious process, characterizing clinical findings of pathological changes during transition period. Mammary quarters of the BAC+ group presented higher percentages of positive reactions to CMT in weeks +1 and +2, and higher MSCC values and are associated with infection of the mammary gland.

CSPE Young Investigator Award Session

CSPE Young Investigator Award Session

Prevalência de aglutininas anti-Leptospira interrogans em cães de Belo Horizonte, Minas Gerais, 2001 a 2002

Avaliou-se a prevalência de aglutininas anti-Leptospira interrogans nos cães recolhidos pelo Centro de Controle de Zoonoses nas nove regionais administrativas de Belo Horizonte, em diferentes épocas do ano. As áreas de prevalência de cães reagentes foram correlacionadas às áreas de saneamento ambiental, usando recursos georreferenciamento. As amostras de sangue dos 3417 cães, coletadas no período de setembro de 2001 a setembro de 2002, foram processadas pela técnica de soroaglutinação microscópica, encontrando-se 13,1% de positividade. As sorovariedades Canicola, Ballum, Pyrogenes e Icterohaemorrhagiae foram as mais prevalentes. As mais altas prevalências ocorreram nas regionais Centro-Sul (22,5%), Leste (19,1%) e Nordeste (13,2%). A menor prevalência foi observada na Regional Pampulha (8,2%). Os meses com maior percentual de cães reagentes foram dezembro/2001 e janeiro/2002, período de maior precipitação pluvial e temperaturas médias mais elevadas. As áreas de maior risco coincidiram com as regiões de vilas, favelas e bairros da periferia onde existia deficiência de saneamento ambiental.

Evaluation of the efficacy of two leishmanins in asymptomatic dogs

There are few studies in dogs concerning leishmanin skin test. We evaluated and compared the efficacy of two leishmanin preparations for the detection of dog Leishmania cellular-mediated immunity. Clinically healthy dogs living in an endemic area were studied. A leishmanin preparation 1 (3×10 8 promastigotes/ml) was superior to a leishmanin preparation 2 (5×10 6 promastigotes/ml), measured as the percentage of positive reactions and the diameter of the induced induration. The leishmanin skin test is a valuable tool, although the results show that the degree of response, as it has been shown in human beings, depends on the preparation used.

Pro position: syncope - a tilt test is indispensable

The most frequent kind of syncope is the so-called “neurally mediated” (vasovagal) syncope; head-up tilt testing has become an effective, safe and non-invasive test for the diagnosis and study of vasovagal syncope. Most authors define the hemodynamic pattern triggered by the tilt test by describing the relation between heart rate and blood pressure. The diagnostic value of tilt table testing is high: in patients with unexplained syncope the percentage of positive reactions to tilt testing lies between 82 and 85%. The specificity of the method is between 95 and 95%. Tilt table testing significantly reduces the number of patients with unexplained syncope. The objective findings of the test provide insight into the mechanism of vasovagal syncope, a differentiated choice of therapy and possibly an evaluation of the applied therapy. Thus tilt table testing is an indispensable diagnostic tool for unexplained syncope.

Failure to identify non-bovine reservoirs of Mycobacterium bovis in a region with a history of infected dairy-cattle herds

The State of Texas had the most (cumulative) tuberculous cattle herds of any state in the United States during the decade ending in 1997. Of the cumulative 18 infected herds in Texas, 12 herds were concentrated in El Paso County (designated the ‘El Paso milkshed’). To identify whether non-bovine reservoirs were a source of Mycobacterium bovis infection of cattle in this region, an investigation was conducted on the premises of 14 dairy herds (12 tuberculous and 2 non-affected herds) between May 1995 and June 1997. None of the 670 mammalian, avian and environmental (soil, water and air) samples collected and cultured from the premises of these herds was positive for the presence of M. bovis. None of the 119 human urine samples obtained from employees of these dairies was culture positive for M. bovis. Of 124 dairy-farm workers with tuberculin skin-test results, 48 showed positive test results. There was, however, no difference in percentages of positive skin-test results between farms without, and farms having, bovine tuberculosis within the last two years or longer. The percentage of positive reactions did not increase with length of time employed at a dairy with a history of confirmed tuberculosis. These findings suggest that non-bovine reservoirs appear not to be a factor responsible for tuberculosis of cattle in the El Paso milkshed.

Differentiated contact allergy lists serve in quality improvement

Through cooperation between the German Contact Dermatitis Research Group (DKG) and the Information Network of Departments of Dermatology (IVDK), results of standardized patch tests performed by the participating centres are centrally recorded in Germany. For this study, data from 24 departments of dermatology (19678 patients) were evaluated retrospectively and separately for 1995 and 1996. With decreasing frequency, nickel, fragrance mix, balsam of peru, and thimerosal yielded positive reactions most often; surprisingly high numbers of positive reactions were also seen with amerchol L-101 and palladium. Differentiated lists of allergens were compiled for 1995, referring to subgroups of patients (defined by gender, age, localization of eczema, geographical region, occupation, sensitization) and particular problems. In men, percentages of positive reactions were markedly lower for nickel, fragrance mix and balsam of peru than in women. Younger patients reacted more often to thimerosal and older ones to topical medical preparations. Medical allergens were also often positive in patients with leg eczema, whereas occupational allergens were found more frequently in patients with hand eczema. A comparison of positive reactions obtained in distinct geographical regions was problematic because of differences between test populations. The spectrum of allergens found in office workers was similar to that of the whole test population. Patients with positive reactions to nickel and fragrance mix had more positive reactions to unrelated allergens than the total test population. Sex- and age-adjusted frequencies of sensitization revealed a decrease in reactions to nickel and an increase in reactions to mercury allergens from 1995 to 1996. The clinical relevance of mercury reactions was often not apparent. Differentiated lists of allergens can be used to improve the quality of diagnostic and prophylactic procedures in allergic contact dermatitis.

Salmonella typhimurium agglutinins in exotic bird sera in the USA.

A preliminary survey of 2,407 psittacine bird sera for Salmonella typhimurium agglutinins has been reported.’ The purpose of the current survey was to obtain additional data on psittacine bird sera and to expand testing to include other types of exotic birds. The 3,915 psittacine bird sera and the 239 pigeon and dove sera tested were selected from those submitted to the Texas Veterinary Medical Diagnostic Laboratory (TVMDL) for Chlamydia testing as previously described. The 17 ostrich sera were submitted specifically for Salmonella serology because of an existing disease problem. The 7 emu sera were submitted for Salmonella serology for a health status check. The whole bacterial cell-stained antigen and the slide agglutination testing methods were used as previously described. Antigen was purchased from the University of Minnesota and stained at the TVMDL. The results on all types of birds are shown in Table 1. Positive reactions (complete agglutination) occurred in sera from 16 (3.3%) of 489 African gray parrots submitted singly and 23 (28.75%) of 80 submitted from a breeder group; 8 (0.7%) of 1,222 Amazon parrots; 1 (0.7%) of 141 cockatiels; 2 (0.4%) of 566 cockatoos; 1 (0.4%) of 227 conures; 1 (0.2%) of 636 macaws; 1 (3.0%) of 33 Senegal parrots; 1 (unspecified parrot type) (0.2%) of 521 mixed types of psittacine birds; 6 (2.5%) of 239 pigeons and doves; and 1 (5.8%) of 17 ostriches. Geographic locations of serologically positive birds, which were from 12 states widespread across the USA, are not shown. Equivocal reactions (partial agglutination) were found in sera from 3 African gray parrots, 8 Amazon parrots, 3 macaws, 1 Pionus parrot, 2 parrots of unspecified type, 2 pigeons and doves, and 1 ostrich. All of the 7 emu sera were negative. The overall percentage of positive reactions in psittacine bird sera was comparable to that reported previously. Again, a group of Congo African gray parrots had a high percentage of reactors. This group was established in a breeder facility, whereas the first such group reported was a newly imported group. The Congo African gray parrot appears to be highly susceptible to S. typhimurium infection. The positive serologic results indicate that Amazon parrots and pigeons/doves also probably are important hosts of S. typhimurium. Because of the small numbers of cockatiel and Senegal parrot sera tested, it is not clear how important these psittacine bird types are as hosts of S. typhimurium, although the percentages of positive results were respectively comparable to those of Amazon parrots and African gray parrots. Salmonellosis caused by S. typhimurium can be a problem

The use of an immunological technique in order to evaluate the predation on Eupoecilia ambiguella (hbn.) (Lepidoptera: Cochylidae) in vineyards

During 1991 and 1992, investigations were conducted in two vineyards of southwestern Germany to determine the predation pressure of selected arthropod species on Eupoecilia ambiguella (Hbn.) (Lepidoptera: Cochylidae), a serious pest of grapevine. Predation was detected by an antiserum, which was used in the Enzyme-Linked Immunosorbent Assay (ELISA). The test was carried out with four predatory species, which are common on the flower and fruit of the investigated grapevines. The percentage of positive reactions when testing 698 animais was 4.4% for Orius minutus (Heteroptera: Anthocoridae), 10.3% for larvae of Chrysoperla carnea (Planipennia: Chrysopidae), 15.1% for Aptus mirmicoides (Heteroptera: Nabidae) and 5.8% for Forficula auricularia (Dermaptera: Forficulidae). Because of the extreme polyphagy of the species under study and the fact, that the assays were not very sensitive, the immunological results alone are insufficient for the evaluation of the importance of the predators asantagonists of Eupoecilia ambiguella.

Immunological and respiratory changes in tea workers.

Immunological status and respiratory function were studied in 26 female nonsmokers employed in processing different types of tea. Skin tests with tea-allergens demonstrated the highest percentage of positive reaction to sage (45%), gruzyan (40%), mentha (35%), and dog rose (10%). Among 17 skin-tested control workers, 23% had positive skin reaction to sage, 19% to gruzyan tea, 20% to mentha and 11% to dog rose and Indian teas. Serum levels of total IgE were increased in 27% of the tea workers and in 7% of the control subjects. Prevalence of almost all chronic respiratory symptoms was higher in tea workers with positive skin tests than in those with negative skin tests to tea allergens. Tea workers with positive skin tests to tea allergens had larger mean acute reduction over the Monday workshift in flow rates (MEF50%: -11.9%; MEF25%: -20.6%) than in those with negative skin tests (MEF50%: -5.7%; MEF25%: -16.7%), thus suggesting an obstructive effect mostly located in smaller airways. Bronchoprovocation testing with different tea allergens provoked acute reductions of ventilatory capacity in four out of six subjects tested. Relative fall over a 90-min post exposure was greater in MEF25% (ranging from 13% to 67%) than in MEF 50% (ranging from 9% to 45% of the control values).

Estudio de dos antigenos de la fase levaduriforme delHistoplasma capsulatumpara pruebas cutaneas

The results of skin tests with two antigens of the yeast phase of Histoplasma capsulatum are presented. Both antigens were able to fix complement and form precipitating bands in the presence of sera from patients with active histoplasmosis. Their sensitivity was lower than the metabolic antigen usually employed in serology. Results of skin tests obtained with both yeast phase antigens and a standard histoplasmin coincided in animals infected with H. capsulatum. Only one cross reaction was observed in animals inoculated with Paracoccidioides brasiliensis. Skin tests in humans were conducted on patients with and without mycotic disease. The percentages of positive reactions in patients with histoplasmosis were not significantly different between control histoplasmin and whole cell extracts. In the patients with non mycotic diseases the frequency of positive tests varied between 28.8% and 32%, which agrees with previous statistical data for the general population of the area. Equally the positive percentage of 55% and 68% in patients with paracoccidioidomycosis coincided with the results of previous studies. The histological patterns of these skin tests showed that they were produced by cell mediated hypersensitivity. The sensitivity of a whole yeast cell extract was similar to histoplasmin L48, but its preparation was quicker and easier to perform and it had no foreign substances from the culture medium, so we think that it would be easier to standardize it chemically.

Cellular Immunity in Children with Acute Rheumatic Fever and Rheumatic Carditis

Summary: Cell-mediated immunity (CMI) was examined in 74 children with acute rheumatic fever (ARF) grouped as with or without carditis and inactive disease with valvular lesions and 26 healthy controls of the same age. Absolute lymphocyte count, skin tests with PPD, Candida, and streptokinase streptodornase (SK-SD) antigens were employed. The lymphocyte transformation test was performed by using phytohemagglutinin (PHA), SK-SD, Candida, and cardiac antigens, and incorporation of tritiated thymidine into DNA was measured. Absolute lymphocyte counts in all groups were not significantly different than those of controls. Skin test responses to PPD, Candida, and SK-SD antigens were significantly decreased in patients with rheumatic activity. In contrast, inactive rheumatic patients with valvular lesions showed higher percentages of positive reactions which were not significantly different than those of the healthy controls. The in vitro response to PHA was decreased in active rheumatic fever (RF) patients, whereas patients with inactive RF with valvular lesions showed a hyperactivity to this mitogen. Patients with inactive RF with valvular lesions also exhibited an exaggerated cellular reactivity to SK-SD antigen, but the patients in active groups showed more of a decreased reactivity than did the controls. Patients with evidence of rheumatic carditis exhibited the same degree of cellular reactivity to these antigens and mitogen as did patients without clinical evidence of rheumatic heart disease. Candida did not cause significant stimulation of blastic transformation in any of the study groups. The blastic transformation response to heart homogenates was present in 25% of the cases with active rheumatic carditis, in 15% without carditis, and in 46% of the patients with inactive valvular lesions. Plasma from the patients with active RF caused inhibition of the in vitro response of the normal lymphocytes to PHA. In the last few years, it has become increasingly apparent that, in addition to the well documented alterations in humoral immunity, ARF is also accompanied by abnormalities in cell-mediated immunity (CMI) where the precise significance in pathogenesis of rheumatic carditis remains controversial. Speculation: Patients with active rheumatic fever may have depressed cellular immune responses both in vivo and in vitro to PHA and specific antigens. Observations on the responses to SK-SD and heart homogenate in inactive rheumatic fever patients suggest that patients with rheumatic carditis build up a cellular immune response to the heart. Our findings also suggest that the possibility of lymphocyte sensitization by heart tissue antigens might play a part in the pathogenesis of rheumatic carditis. But the reason for hyporeactivity and the exact link if any between lymphocyte abnormalities and tissue lesions of rheumatic carditis remain to be elucidated.

Exposure to dust-borne bacteria in agriculture. II. Immunological survey.

In order to investigate whether high exposure to Erwinia herbicola causes sensitization in grain handlers, immunological tests (agargel precipitation, complement fixation, passive cutaneous anaphylaxis, and intradermal) with the extracts of these bacteria were performed in different groups of grain workers and in other groups of population. Tests with extracts of grain dust and other microorganisms were also performed. Grain workers showed in all the tests high incidence of positive reactions to E. herbicola, being significantly higher, as compared with unexposed subjects. Different actinomycetal and fungal extracts gave lower percentages of positive reactions. Skin reactions to E. herbicola were significantly correlated with the reactions to grain dust and showed a close relationship with the degree of exposure. The grain workers with respiratory symptoms reacted more frequently to E. herbicola than asymptomatic ones, both in intradermal and precipitation tests. Thus, these bacteria should be considered as a factor increasing risk of the respiratory disorders among grain handlers.

The Most Important Allergens in Allergic Rhinitis

The distribution of allergens, found on thorough allergy work-up in a series of 770 patients with seasonal and perennial nasal symptoms, is reported. The percentages of positive reactions to grass, tree, and herb pollens were equally high (30--40%) but, clinically, pollens from grasses (Timothy, Alopecurus, Kentucky Blue and Meadow fescue), birch and mugwort (Artemisia) were the most important. In the Nordic countries house dust is evidently the commonest causative agent in perennial rhinitis but the heterogenous composition of house dust makes it difficult to determine potent allergenic factors. Sensitivity to house dust was present in 44% of the patients; a positive reaction to mite extract in only 10%. Animal danders were not found to be great importance in allergic rhinitis (13--18%). Reactions to moulds were observed in 9% of the patients.

Some observations on the epidemiology of toxoplasmosis in Canada.

Between 1961 and 1974, 11934 samples of serum were tested by the Sabin-Feldman Dye test for the presence of antibodies to Toxoplasma gondii. Analysis of high-titred sera suggested that a 6-year cycle of high disease prevalence occurred across Canada. In addition, a decline in the percentage of positive reactions each year in the Fall. The suggestion that this decline was due to dry conditions during the summer months was supported by the observation that differences in the prevalence of toxoplasma infection in ten Canadian cities were related to their average summer rainfall. The significance of these observations in relation to the epidemiology of toxoplasmosis in this country is discussed. The influence of patient age on the prevalence of infection was also investigated; the results obtained suggested that at least 75% of infants with high antibody titres against T. gondii had obtained these antibodies by placental transfer from their mothers.

Acute Myocardial Infarction Diagnosed by Myoglobinuria

Myoglobin can be found in excess in the urines of some patients with acute myocardial infarction. To test the specificity of this finding, urine specimens were analyzed from 39 patients with provisional diagnosis of myocardial infarction by means of a hemagglutination-inhibition technique with prepared antisera to monkey myoglobin. Of 24 patients with subsequently documented myocardial infarction, 15 had at least one positive determination. None of the 15 patients without infarction had positive tests. Ten of 13 patients with infarction studied within 24 hours of the initial event had positive reactions. The percentage of positive reactions in the infarct group decreased sharply after the first 24 hours. This technique may be of value in rapid screening of patients with possible acute myocardial infarction during early stage of symptoms.