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Calf thymus native DNA was covalently linked with lysine by irradiation with 254 nm light. Thermal melting studies indicated a decrease of 16 degrees C in the Tm of DNA-lysine photoadduct over native DNA. The decrease in Tm was dependent of irradiation dose. The photoadduct was found to be a potent immunogen in experimental animal. Thymine-lysine photoconjugate in DNA-lysine photo-monoadduct appears to be the major immunodominant portion. A strong recognition of DNA-lysine photoadduct was observed with anti-DNA autoantibodies found in the sera of patients with SLE. Thymine-lysine conjugate in DNA-lysine photo-monoadduct appears to provide an immunodominant epitope(s) for SLE autoantibody recognition. The results suggests for the possible involvement of DNA-lysine photoadduct or similar modified structure(s) as a potential trigger for anti-DNA autoantibody production.

Six auto parts manufacturing workers were referred for evaluation of a 6-week history of work-related dyspnea, cough, and fatigue. Two workers also reported fever and weight loss. All six worked in a machining area where a waterbased metalworking fluid was used and recirculated under high pressure, thereby creating an aerosol. Chest radiographs revealed pulmonary interstitial infiltrates in four workers. Lung function tests showed that four workers had decreased diffusing capacity. After removal from the work area, all workers recovered. The metalworking fluid was cultured for bacteria and fungi. Isolates from broth cultures were sonicated to obtain antigen extracts. Serum precipitins to one or more of the microbial isolates were identified in all six workers but not in eight of nine nonexposed control subjects. The most frequent precipitin response (six of six workers) was against antigens of Pseudomonas fluorescens, which was cultured from the metalworking fluid. In all workers, precipitins to at least one other cultured organism were detected; these included Aspergillus niger, Staphylococcus capitas, an acid-fast Rhodococcus sp, and Bacillus pumilus. This represents the first report of hypersensitivity pneumonitis associated with industrial exposure to aerosolized metalworking fluid. Observed precipitin responses to a variety of microbial contaminants in metalworking fluid strongly suggest a causative role for microbial antigens in the induction and elicitation of this manifestation of hypersensitivity pneumonitis.

Lung mucociliary clearance was measured in 15 pigeon fanciers. The study group was subdivided into two: a precipitin-positive group (n = 10; mean +/- SEM age 45 +/- 5 years) with circulating blood precipitins and a precipitin-negative group (n = 5; mean +/- SEM age 40 +/- 3 years) without. Clearance was measured using an objective, noninvasive radioaerosol technique. The data for both groups were compared with those of matched control groups of healthy subjects. The mean +/- SEM area under the tracheobronchial retention curves (AUC) over the 6-h observation period was 257 +/- 27 %h for the precipitin-positive group compared with 177 +/- 16 %h for its control group (p = 0.02)--a high AUC value denoting slow clearance. That for the precipitin-negative group was 282 +/- 34 %h compared with 150 +/- 15 %h for its control group (p = 0.02). Our study illustrates in pigeon fanciers involvement of the conducting airways in that a major defense mechanism of the airways--namely, mucociliary clearance--is substantially compromised. The presence or absence of precipitins appears not to be related to the degree of mucociliary clearance impairment.

The cellular localization of the tube precipitin (TP) and complement fixation (CF) antigens of Coccidioides immitis was examined by immunoelectron microscopy with murine immunoglobulin G1 monoclonal antibodies directed against the TP and CF antigens, respectively. Immunoelectron microscopic analyses of saprobic- and parasitic-phase cells showed that the TP antigen is present at a high concentration within the inner cell wall layer and along the plasma membrane. The antigen was also detected, at a lesser concentration, within cytoplasmic vacuoles. In contrast to the predominant localization of the TP antigen in the cell walls, the CF antigen residues primarily within the cytoplasm, where it appears to be dispersed throughout the cytoplasm rather than associated with a specific cytoplasmic organelle. A sparse amount of the CF antigen within the inner cell walls was also demonstrable. The localization of the TP and CF antigens throughout the morphogenetic phases of C. immitis has important implications in antigen production and in analyses of host response in coccidioidomycosis.

Background: The enzyme linked immunosorbent assay (ELISA) for detecting IgG antibodies to Aspergillus fumigatus is more sensitive than the measurement of Aspergillus precipitins. The relation of the results from both techniques to the clinical pattern of disease in a large unselected group of patients from a large referral centre is unknown., Methods: The clinical relation of precipitins to Aspergillus fumigatus to clinical disease was determined retrospectively in 98 patients attending a primary referral centre. Precipitin results were compared with the specific IgG antibody to A fumigatus in 88 of the sera. Precipitins were determined by the agar gel double diffusion test and specific IgG antibody to A fumigatus by a quantitative ELISA., Results: Precipitins were detected in the unconcentrated serum of 51 patients. Thirty nine of these had a mycetoma or allergic bronchopulmonary aspergillosis, 34 having specific IgG antibody to A fumigatus more than the control range. Forty seven patients had precipitins only after threefold concentration of serum or to only one of the four A fumigatus antigen extracts. Most of these had specific IgG in or near the control range. Thirty of these had A fumigatus skin test negative asthma or bronchiectasis, in which aspergillus was probably not pathogenic. There was a close relation between the level of antibody detected by the ELISA and the number of precipitin lines., Conclusions: This study reaffirmed the supportive role of aspergillus precipitins in the diagnosis of pulmonary aspergillosis. No additional benefit in the routine use of the ELISA was seen. It also showed that care should be taken in interpreting positive precipitin results from concentrated serum and that using several rather than one A fumigatus antigen extract is helpful for identifying allergic aspergillosis.

Precipitating antibodies to avian antigens play a controversial role in the diagnosis of bird breeder's disease (BBD). In order to establish the sensitivity, specificity and accuracy of precipitins in our laboratory, we conducted a prospective study including 128 sera received in 1988 for determination, by immunoelectrophoresis, of avian precipitins. Accurate information was obtained for 90 patients; definitive clinical diagnosis was given by the patient's own physician. We found a high sensitivity (86%), specificity (93%) and accuracy (92%) of avian precipitins in the diagnosis of BBD. Bayes' theorem was applied to determine the predictive value of the test with varying disease prevalence, and established that precipitins were particularly valuable for low or medium a priori probability. Using the receiver operating characteristic (ROC) curve we evaluated the effects of varying the positivity threshold of precipitins. The threshold used in this study appeared to offer the best compromise between sensitivity and specificity. These results suggest that the diagnostic value of avian precipitins in the work-up of BBD should be reconsidered, also because they represent a simple, cheap and non-invasive diagnostic test.

A rapid enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG antibodies against a cytoplasmic antigen of Candida albicans. The optimum conditions and time required for each step were investigated. Pre-equilibration at 37 degrees C and constant agitation of immunoreactants resulted in a total test time of 1 h for examination of single serum dilutions. Initial binding of the antigen at 37 degrees C to the solid phase occurred within 4-6 min and was dependent on concentration. A serum dilution of 100-fold resulted in adequate discrimination between precipitin test-positive and -negative sera. Interaction of antibody and the bound antigen was maximal after 6 min incubation at 37 degrees C and was dependent upon the precipitin titre of the serum. Ten minutes was selected as the optimal incubation time for each of the stages, by which time maximal binding had occurred, irrespective of antibody affinity for antigen. The ELISA was completed by incubation at 37 degrees C for 10 min with alkaline phosphatase-conjugated anti-human IgG. Discrimination between positive and negative test sera was achieved by incorporating in each test run precipitin test-positive and -negative reference sera from groups of persons with or without C. albicans colonization or infection. Closest agreement between sera positive for C. albicans precipitins by counter-immunoelectrophoresis and the rapid ELISA was seen when reference negative sera were selected from non-colonized individuals.

Antigenic relations between meningococci, serogroups Z and 29E, have been studied with the use of serological methods. The thermolabile fractions of meningococci belonging to the above serogroups have been shown to contain common antigenic determinants which ensure the presence of serological cross reactions. Cross-reacting precipitating and agglutinating antibodies can be completely removed by the adsorption of meningococcal antisera, serogroups Z and 29E, with the cultures of heterologous serogroups. In the antisera adsorbed by meningococci belonging to heterologous groups a decrease in the titers of agglutinins, hemagglutinins and precipitins, particularly pronounced in adsorbed serogroup 29E antisera, has been observed.

Using counterimmunoelectrophoresis (CIE), serum antibodies to rabbit thymus extractable antigens were detected in 15% (38/259) of patients with chronic liver disease (CLD) of various aetiologies and 33% (41/124) of patients with miscellaneous connective tissue diseases (CTD). A remarkable diversity of precipitating systems was apparent among cases with the two classes of disorders. All the five systems found in CLD (XR, XR2, SS-B, XR3, XR4) were associated mostly with immunological hepatic disorders. In the 52 autoimmune hepatitis cases, XR was mainly detected (29%), whereas in the 82 primary biliary cirrhosis patients the whole spectrum of reactivities was represented (XR: 11%, XR2: 10%, SS-B and XR3: 2% each, XR4: 1%). XR proved to be closely associated with smooth muscle antibodies (SMA, detected by indirect immunofluorescence on rat kidney sections) both qualitatively and quantitatively. Since all SMA positive sera with anti-actin specificity (SMAT, SMAG) were XR positive and purified actin could absorb out XR CIE reactivity, the hypothesis is made that a cross-reaction occurs between XR antigen and actin epitope(s).

A cross-sectional epidemiological study was carried out on 2932 farmers (response rate 92%) living in Northern Italy. A questionnaire on respiratory symptoms was supplied, chest X-ray taken and simple spirometry tests made. Thirty-nine subjects reported attacks of breathlessness associated with fever after exposure to mouldy hay; thirty-six had a clinical history of farmer's lung and X-ray and/or respiratory function changes indicative of chronic farmer's lung; 113 were classified as having bronchial asthma. These 118 subjects and a random sample of 131 non-symptomatic subjects were examined by intracutaneous skin tests and double diffusion precipitation tests with antigens associated with farmer's lung. All sera positive by precipitation were examined by immunoelectrophoresis, counterimmunoelectrophoresis, and C1q binding test, and Bovine conglutinin test in solid phase for the detection of circulating immunocomplexes. 27.8% cases of chronic farmer's lung, 4.4% of cases of bronchial asthma and 2.3% of non-symptomatic subjects showed precipitating antibodies against farmer's lung antigens. Of the precipitin-positive subjects, the majority had precipitating antibodies against Micropolyspora faeni. No differences in immunoelectrophoregrams in number and pattern of precipitation arcs for M. faeni were found between chronic farmer's lung and bronchial asthma subjects. Circulating immune complexes were present in 50% of chronic farmer's lung patients, 40% of those with bronchial asthma and 33.3% of non-symptomatic subjects. Three farmer's lung subjects (9.3%) showed immediate skin-test reactions to rural environmental allergens.

We have used crossed immunoelectrophoresis to identify and establish the relative amounts of serum proteins secreted by a differentiated cell line (Fao) derived from a Reuber H35 rat hepatoma. Our results show that these cells secrete at least 15 plasma proteins. Ten of these: albumin, alpha 1-antitrypsin, alpha 1-lipoprotein, alpha 1-macroglobulin, alpha 1-antichymotrypsin, GC-globulin (transcalciferin), fibronectin, hemopexin, transferrin and the C3 component of complement have been identified. To examine the feasibility of using the Fao cell line as a model for studies on the regulation of hepatic protein secretion, we measured the relative amounts of 10 serum proteins secreted into the growth medium after exposure of these cells to dibutyryl cyclic AMP, hydrocortisone and a combination of both compounds. We also examined the effects of growth temperature (33.5 degrees, 37 degrees and 39 degrees C) and the removal of fetal calf serum from the growth medium on the relative amounts of these proteins secreted. We found that the rates of secretion of most of the serum proteins were altered by one or more of the treatments used in these experiments. In addition, detectable levels of secretion of three serum proteins, fibronectin and two unidentified, occurred only under certain of the experimental conditions. These results demonstrate that the pattern of proteins secreted from Fao cells can be experimentally altered and indicate that this cell line may be a useful model for studies on the control of hepatic protein secretion.

A report is given about serologic results of 27 aspergilloses, mostly aspergillomas. The evidence of antibodies directed against aspergillus species was carried out by radial diffusion according to OUCHTERLONY and immunoelectrophoretically. Filtrate antigens ("metabolic antigens") were used troughout. The positive yield lies in about 90%. Regarding the criteria for evaluation no positive reactions were seen in a control group of 140 patients with serious tuberculosis and other lung disorders. The method is emphasized as diagnostic mean for clearing up shadows of the lung and for pathogenetic control of aspergillus--grown from lung materials.

Potent immunogenicity of certain extracellular 'chymotrypsin-like' enzymes of Micropolyspora faeni are demonstrated. One of them, Enzyme 1 seems particularly active in stimulating the formation of percipitins after intratracheal exposure in rabbits. Man or cattle exposed naturally to mouldy hay, either with or without clinical farmer's lung symptoms show a rather constant immunological reaction against Enzyme 1 and partly also against others of the same group. The detection of specific percipitins against these enzymes is not likely to improve the diagnostic value of the standard farmer's lung serology. Possible implications of these proteolytic enzymes in the pathogenesis of farmer's lung are discussed.

Two-dimensional immunoelectrophoresis was utilized to study precipitins in hyperimmune rabbit serum made against chlamydiae and from patients with chlamydial infections. An antigen of Triton X-100-solubilized L2/434/Bu organisms with an electrophoretic mobility of 0.65 relative to bovine serum albumin at pH 8.6 was excised from the agarose gel of electrophorograms as antigen-antibody complexes and used to immunize rabbits. A monospecific antiserum to antigen 0.65 was obtained that reacted with Trachoma-LGV strains L2/434/Bu, B/TW-5/OT, and K/UW-31/Cx, but not with the mouse pneumonitis (Nigg) strain or the psittacosis strain meningopneumonitis (Cal-10). The Trachoma-LGV specificity of antigen 0.65 was further shown by indirect immunofluorescence straining with the monospecific antiserum of chlamydial inclusions in infected HeLa cells. Precipitins with a specificity for antigen 0.65 were indentified in 15 of 18 sera from patients with diagnosed Chlamydia trachomatis infections LGV, trachoma, nongonococcal urethritis, and nongonococcal cervicitis by using monospecific antiserum to antigen 0.65 in the peak suppression test. Thus, antigen 0.65 appears to be a Trachoma-LGV-specific antigen that has considerable promise for serodiagnosis.

Precipitins against avian antigens in sera from patients with extrinsic allergic alveolitis, asymptomatic pigeon and chicken breeders and from control individuals were tested with different antigen extracts in six laboratories by a variety of different methods. Eighty percent of the results coincided in identifying the positive sera from patients and 90% in identifying the controls. It seems possible therefore to exchange results among experienced laboratories with fair confidence.

We have examined sera from 61 patients with systemic vasculitis for precipitating antibodies to components of saline tissue extracts. Precipitins were rare in patients with polyarteritis nodosa (PAN) and their absence helped to distinguish PAN from vasculitis associated with other connective tissue diseases. Precipitins were detected in some patients with other vasculitides. Previously described precipitating antibodies (anti-Ro [SSA] and anti-La [SSB]) were restricted to a few patients with features of systemic lupus erythematosus (SLE). A different, as yet unidentified, precipitin which reacted with a component of rabbit thymus extract but not calf thymus or human spleen extracts was detected in many patients with rheumatoid disease. This precipitin was present in all patients with active rheumatoid vasculitis (RV) as well as 52% of patients with uncomplicated but active rheumatoid synovitis. Higher titres of precipitating antibody were present in patients with active RV than those with inactive RV or uncomplicated rheumatoid synovitis, and serial studies showed a good correlation between a fall in antibody titre and healing of vasculitis with treatment. These studies suggest that this unidentified precipitin may be an important marker of RV.

The incidence of serum antidust and antifungal precipitins was determined by counterimmunoelectrophoresis in 317 atopic and nonatopic subjects of three geographic areas (north central, southern, and western United States). The selected lyophilized crude antigens employed were from house dust, Micropolyspora faeni, Candida albicans, Alternaria tenuis, Aspergillus fumigatus, Puccinia coronata, Cantharellus cibarius, and Amborsia trifida. Antidust precipitins were detected with high frequency in atopic and nonatopic subjects of each geographic area (48 to 71 percent of different population subgroups). Precipitin reactions were generally intense and often multiple, in keeping with the marked heterogeneity of the crude dust antigen employed. Antidust precipitins were also present in serum fractions precipitated with ammonium sulfate and in IgG-rich fractions obtained by gel filtration (Sephadex G-200) and diethylaminoethyl-cellulose chromatography. Precipitins against crude somatic fungal and actinomycetic antigens were detected with considerably less frequency in all populations surveyed, considerably less frequency in all populations surveyed, and antiragweed precipitins were not detected. Our results suggest that prolonged environmental exposure to diverse, ubiquitous organic dusts results in a "normal" serum precipitating-antibody response. They also extend our previous finding of a high precipitin response against organic dusts in residents of the Gulf south area compared to other geographic areas.

Sera of patients with primary biliary cirrhosis (PBC) were examined for the presence of precipitating antibodies to sonicated rat liver mitochondrial (M) fraction. Three distinct precipitating systems observed in double immunodiffusion were identified and called M-A, M-B and M-C. Unsonicated mitochondria did not form precipitin lines. Precipitating system M-A was found in nineteen of twenty (95 percent) sera from PBC. The mitochondrial antigen of M-A system had the unusual property of being resistant to enzymatic digestion with deoxyribonuclease (DNase), ribonuclease (RNase) and trypsin under standard conditions. The titres of antibody to M-A antigen correlated (P less than 0.05) with titres of mitochondrial immunofluorescence staining on unfixed mouse kidney sections. Precipitating systems M-B and M-C were present in seven of twenty ribonuclease and trypsin but resistant to ribonuclease indicating that it could be DNA-protein complex. The M-C antigen was destroyed by trypsin suggesting its protein character, but it was difficult to determine if nucleic acids might also be associated with antigenicity. The antibodies to mitochondrial antigens were not present in normals (fifteen health adults), systemic lupus erythematosus (forty patients), rheumatoid arthritis (fifteen patients) and chronic liver diseases (fifteen patients). The antibodies did not show identity with antibodies to ribosomal ribonucleo-protein and other known nuclear antigens previously reported. The data confirm previous reports concerning the heterogeneity of mitochondrial antibodies present in sera of patients with PBC. The antibody to M-A antigen appeared to be a diagnostically useful immunological marker since it was present in the majority of patients with PBC.

Precipitating antibodies to Mi-1, a protein antigen purified from calf thymus nuclear extract, have been reported in a small percentage of patients with dermatomyositis (DM) but not in patients with other connective tissue diseases or controls. Mi-1 shares certain characteristics with immunoglobulin, including the ability to react with rabbit anti-bovine immunoglobulin G (BIgG). A more extensive survey for anti-Mi-1 has been performed, involving 51 normal controls, 67 patients with polymyositis (PM) or DM, 47 patients with rheumatoid arthritis (RA), 41 SLE patients without any other precipitating antibodies to saline extractable tissue antigens on routine testing, and 247 patients, many with SLE, known to have other precipitins. Anti-Mi-1 was found in 13 patients from the latter group (5.25%) and two patients with PM or DM (3.0%), and was not found in other groups. It was found in seven of 95 (7.4%) with anti-nRNP, three of 32 (9.4%) with anti-Sm (with or without anti-nRNP) and three of 120 (2.5%) with anti-Ro (SSA). Anti-Mi-1 cross-reacts directly with BIgG but differs from ordinary rheumatoid factor in its frequent reaction with Fab2 fragments and restricted species specificity. Thus, anti-Mi-1 can be found in patients with diseases other than DM, including SLE, most often in patients with antibodies to nRNP.

On examination of Bactec blood cultures for pneumococcal antigen by countercurrent immunoelectrophoresis the consistent presence of a non-specific protein band caused problems with the interpretation of results, even in laboratories experienced in performing countercurrent immunoelectrophoresis. When the Bactec blood culture system is used, countercurrent immunoelectrophoresis should not be relied on for the detection of pneumococcal antigen.

Haemolymph from the elongate clam, Tridacna maxima (Röding) readily precipitates with H-blood group substances, pneumococcus type XIV polysaccharide, human milk and salivas, and with a number of polysaccharides which contain the O-SS-D-galactopyranosyl-(1-6)-D-galactose structure. Precipitation has been demonstrated using both gel diffusion and quantitative precipitin methods. T. maxima haemolymph strongly agglutinates human erythrocytes and haemagglutination can be inhibited by the same preparations which precipitate with the clam extract. Precipitins and haemagglutinins are inhibited by N-acetyl-D-galactosamine and by D-galactose residues preferably in ss-linkage. After agar gel immunoelectrophoresis at pH 8.6, T. maxima precipitin arcs are found in the alpha-region. Precipitation and inhibition results suggest that T. maxima extract and purified precipitin, may find widespread application in the study of many biologically important carbohydrates and glycoproteins.

It has recently been reported that liposomes containing membrane components from cytolytic T-cell (TC) clones could transfer lytic activity to noncytolytic T- and B-cell lines, strongly suggesting that TC possess membrane-associated molecules which noncytolytic lymphocytes lack and which play a critical role in the lytic mechanism. It was thus of interest to compare the membrane-associated proteins from TC-lines to those of noncytolytic helper T-cell (TH) lines to determine whether any membrane-associated proteins unique to TC could be identified. Cells from three TC-lines and four TH-lines were internally labelled with [35S]methionine and then disrupted by hypotonic lysis. Low-density (plasma membrane enriched) and high-density (endoplasmic reticulum enriched) membrane fractions were isolated from each cloned cell line and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Two proteins were identified which were prominent in the membrane fractions from each of the three TC-lines but not in the membrane fractions from any of the four TH-lines. One of these, p215, migrated as a broad band with an apparent mol. wt of 215,000. The other, p24, migrated as a sharp band, or tightly spaced doublet, with an apparent mol. wt of 24,000. Immunoprecipitation studies using monoclonal antibodies to T200, LFA-1, Thy 1 and Lyt 2 suggested that p215 was a variant of T200 found on TC-lines but not on TH-lines. Treatment of solubilized membrane proteins from TH-lines with anti-T200 precipitated a 185-kD protein seen on each of the TH-lines but on none of the TC-lines. In contrast, p24 was not precipitated by any of these monoclonal antibodies. It therefore appears that p24 represents a previously unidentified protein which is strongly expressed by TC but not by TH and is thus deserving of further study as to its functional significance.

A polyethylene-glycol insoluble serum fraction was studied in patients with sickle cell anaemia during the steady state of the disease. The levels of C1q-precipitins were normal but increased amounts of proteins, IgM C3 and factor B were detected in this immune complex enriched serum fraction. These findings are a sign that circulating immune complexes can be detected even in the asymptomatic period of the disease.

Precipitating antibody concentration responses to crude northern fowl mite extract (CME) and bovine serum albumin (BSA) injections were compared in White Rock and Fayoumi hens with two-dimensional immunoelectrophoresis and rocket electrophoresis. The effect of CME injections on northern fowl mite population development was also determined. White Rock and Fayoumi hens developed similar antibody concentrations in response to intramuscular injections of BSA according to serum samples analyzed with two-dimensional immunoelectrophoresis. Rocket electrophoresis analyses of pooled serum samples showed significant differences between slopes of White Rock and Fayoumi pools for CME and BSA injections, suggesting differences in antibody-antigen interactions. Fayoumi hens injected with CME, 78, 50, and 14 days prior to experimental infestation with 2,000 northern fowl mites/bird supported significantly fewer mites than BSA-injected hens, although mite populations were low on both treatment groups. Injections of CME had no effect on mite population development on White Rock hens, even though CME-specific antibodies were detected. Although White Rock hens supported significantly greater mite numbers than Fayoumi hens, the difference was not attributed to anti-CME antibody activity alone.

A group of patients with serum precipitins against M. faeni culture filtrate antigens and with clinically proven farmer's lung disease was examined. A group of precipitin-negative farmers with comparable antigen exposure and with unrelated forms of pulmonary disease served as control. Immunoglobulins G and A were elevated at first consultation in the majority of the acute cases of farmer's lung. Immunological parameters normalized during corticosteroid medication and antigen avoidance. Autologous complement (C) consumption by M. Faeni antigens proved valuable for diagnostic purposes. Despite normalizing immunological factors and subsiding symptomatology, C-consuming antibody levels remained constant.

The optimum conditions for detection of Candida precipitins by double diffusion and counter immunoelectrophoresis have been established. Counter immunoelectrophoresis was shown to be more sensitive than double diffusion, and its application to routine tests for Candida precipitins to cytoplasmic antigen is recommended.

Antibodies to three major antigens of the non-histone or saline-extractable nuclear antigen (ENA) complex were sought by counterimmunoelectrophoresis (CEP) in three groups of sera which gave different patterns in the immunofluorescence test for antinuclear antibodies (ANA). Precipitins, mainly anti RNP and anti SS-B, were found most commonly (61%) in 70 sera with a speckled ANA pattern but were less frequent (8%) in 61 sera with a homogeneous ANA pattern and exceptional (1%) in 72 sera which showed fibrillar ANA staining. Rim staining was an insensitive indicator of nDNA antibody. An enzyme immunoassay (EIA), specific for anti-SS-B was more sensitive than CEP and identified this antibody in 28 sera, compared with 18 for CEP.

Crossed immunoelectrophoresis was employed in the study of precipitating antibodies against Staphylococcus aureus in sera from 46 patients with S. aureus septicaemia. The occurrence and titres of antibodies were compared to previously reported findings for normal persons. Ten infection-specific precipitins were detected. However, most of these precipitins were detected in low titres and could only be detected during convalescence. When antibodies against a single antigen were measured, titres above the normal level were found in 39.1% - 65.2% of the patients. When the total number of precipitins in each serum was compared to findings in serum from normal persons, 54.3% of the patients had a higher value. Most promising was the precipitin score, considering both the number of precipitins and their titres. This score showed an early rise and was increased above the normal level in 82.6% of the patients. The antibody response against individual S. aureus antigens varied from person to person both concerning titres and time course.

Antibodies against the P1 antigen of the P blood group system have been found in 34% of P2 pigeon breeders' sera and in only 6% of the control group. In pigeon breeders, this anti-P1 activity correlates with immunization to pigeon serum and can consistently be removed by absorption with pigeon erythrocytes, serum or droppings. It is concluded that P1 or a related antigen is present in the pigeon blood and drop-pings and that heavy exposure to pigeon dust, as may occur in pigeon breeders, is one of the factors capable of inducing IgM antibodies to P1 antigen. The clinical importance of this finding remains to be defined.

Detection of serum precipitins to Aspergillus fumigatus by counterimmunoelectrophoresis is compared with the immunodiffusion technique. Eight of nine (89%) sera from patients with proven A. fumigatus infection were positive by both methods. No serum from subjects with other systemic mycoses, bacterial infections, or healthy controls had detectable precipitins. The highest serum precipitin titers were found in sera of patients with the mycetomal and invasive forms of the disease. Detection of A. fumigatus serum precipitins by counterimmunoelectrophoresis compares favourably with immunodiffusion and has the advantage of significantly reducing the time required for results.

One hundred and six asthma patients were studied in Zaria in the Nigerian savanna region. This group resembled hospital attenders in general in containing a disproportionately large number of immigrants from southern Nigeria and students undergoing higher education. Childhood asthma was rare. Asthma started after the age of 19 years in 69 per cent of patients. Twenty-seven per cent gave a history of rhinitis but none had had eczema. Twenty-two per cent gave a family history of asthma. Cutaneous hypersensitivity to house dust supported by a history of attacks being precipitated by dust was found in 41 per cent of patients. Asthma was worst in the rainy season in 45 per cent of patients. Mites were found in mattress dust samples; the mean count was 243 mites per g dust; Dermatophagoides farinae formed 86-6 per cent of the total mite population. The variability of airways obstruction averaged 50 per cent of maximum values for forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF). The median severity of airways obstruction measured as FEV1/VC per cent was four standard deviations below predicted normal. Eighty-seven per cent of patients were positive to prick skin tests with one or more allergens. The commonest reactions were to house dust (58 per cent), house dust mite (45 per cent) and Dermatophagoides farinae (44 per cent). Fifty-one per cent of a group of controls were also positive on skin testing but the pattern of responses was different from the asthmatic patients. This high proportion of reactors is explained by high allergen load. Serum IgE levels were lower in the asthmatics than in a group of healthy controls who showed the very high levels characteristic of some African populations. We suggest that the controls were protected from atopic disease by developing high blocking levels of non-specific IgE, perhaps in response to gut helminths. The clinical pattern of asthma in Zaria is compared with other countries in the tropical and temperate zones. The particular problems of treating asthma in developing tropical countries are discussed.

Tattoo lesions linked to the cetacean poxvirus of bottlenose dolphins regressed without treatment. Two types of regression were observed: (1) The tattoo lesions became raised and blanched, then disappeared along with sloughing skin. (2) When an incision was made through a tattoo lesion, the tattoo disappeared in a zone around the incision. Poxviruses removed from the raised, blanched skin lesions and from typical tattoo lesions were reacted with dolphin serums and examined by immunoelectron microscopy. Antibody was not detected against either of these poxvirus preparations when the dolphins had only typical tattoo lesions. However, after the raised, blanched lesions appeared, serums obtained during the acute or convalescent stages were positive for the poxvirus separated from the lesions. Regression of the typical tattoo lesions was concurrent with antibody conversion.

Since the liver membrane components termed liver-specific protein (LSP) and liver membrane antigen (LM-Ag) have been implicated as target antigens in chronic active hepatitis (CAH), we performed physicochemical and immunological analyses of these and other fractions obtained from liver homogenates. Supernatants were prepared from homogenates of human and rabbit liver by centrifugation at 105,000 g for 1 hr; after gel filtration on Sepharose 6B, the LSP fraction was obtained as the excluded peak I and LM-Ag as an included fraction, peak IIB. Comparison by immunodiffusion with reference LSP and guinea pig antisera to LSP confirmed the similarity of our fractions to reference preparations. Upon SDS-polyacrylamide gel electrophoresis (SDS-PAGE), human and rabbit peak I were found to contain at least 25 distinct protein bands with a wide range of molecular weights (14,000- greater than 100,000) and the other peaks were found to be equally heterogeneous. Thin-layer polyacrylamide gel isoelectric focusing (PAGIF) revealed 35-40 separate bands in both peaks I and IIB with a wide range of isoelectric points (3.5-10.0). These results indicate that liver homogenate fractions such as LSP and LM-Ag can no longer be considered as single protein preparations, and are in fact highly complex mixtures of multiple proteins. Further separation and characterization of such fractions will facilitate identification of liver antigens for use in in vitro immunological assays.