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PubMed1976

Farmer's lung disease in Somerset.

A survey of laboratory records was made to assess the value of the precipitin test and isolation methods in the diagnosis of farmer's lung disease and also to determine its prevalence in the farming population of Somerset. A link was established between the clinical diagnosis as written on the form that accompanied the specimen and the actual number of positive laboratory diagnoses made. Fifty (43%) of the clinically diagnosed patients were serologically positive for farmer's lung during a four-year period. If the clinically diagnosed but serologically negative cases of farmer's lung disease are added to this number, a prevalence of about 23 per 1000 of the farming population of Somerset is obtained.

England↗
PubMed1976

Properties of the gamma haemolysin of Staphylococcus aureus 'Smith 5R'.

Purified gamma haemolysin of Staphylococcus aureus was characterized in relation to the alpha, beta and delta haemolysins. The sedimentation coefficient of the gamma lysin was 2-65, somewhat higher than the S20,w values of 1-4 for freshly purified alpha lysin and 1-8 for the beta lysin. The molecular weight of gamma lysin determined by gel filtration was 45000 daltons. The pI of gamma lysin was 6-0, while that of the alpha, beta and delta lysins ranged from 8-5 to 9-6. The amino acid analysis of gamma lysin was characterized by low levels of methionine and histidine. Methionine was, however, the N-terminus, which suggested that all of the amino acid might be involved in the N-terminal group. The gamma lysin was immunologically distinct from the alpha, beta and delta lysins by quantitative precipitin tests; in Ouchterlony agar gel diffusion tests, single lines of precipitation were observed which showed no evidence of cross-reactions amongst the four haemolysins. Gamma, beta and delta lysins had no affect in mice when injected at increasing doses ranging from 0 to 100 mug. The alpha lysin killed mice, the LD50 dose being 0-60 +/- 0-12 mug, or 27 to 34 mug/kg mouse tissue. Gamma lysin was, however, lethal for guinea pigs when 50 mug quantities were injected intracradially. Gamma lysin also lysed human leucocytes and destroyed C-6 (human lymphoblast) cells.

Amino Acids↗
PubMed1977

Studies on the epidemiology of sandfly fever in Iran. III. Host-feeding patterns of Phlebotomus papatasi in an endemic area of the disease.

Blood meals from 575 Phlebotomus papatasi collected in an Iranian village were identified by precipitin test. The majority of sandfly feedings (57.5%) were on birds, mainly chickens and pigeons. The remaining 42.5% were on mammals (humans, cows, mules, sheep, and goats) or were non-reactive. Calculation of forage ratios of each host species indicated that chickens, equines, and bovines were the preferred hosts of P. papatasi in the village. Results of this study demonstrate that P. papatasi has a much wider natural host range than indicated previously and suggest that this species is an opporunistic feeder and is not strongly anthropophilic. Observations on the diurnal activity of P. papatasi are also presented.

Animals↗
PubMed1987

Schistosomiasis mansoni in the Dominican Republic; prevalence and intensity in the city of Higuey by coprological and serological methods.

The prevalence and intensity of infection with Schistosoma mansoni were determined in a sample of the population of the city of Higuey, Dominican Republic. The quantitative formol-ether stool sedimentation technique of Ritchie, as modified by Knight et al., was performed on stools from 1,025 (65.5%) of 1,563 individuals greater than 1 year old. The highest prevalence rates (21.4%) were observed in women 25-29 years old and in men 15-19 years old (20%). The maximum fecal egg count was in the 15- to 19-year age group, with a geometric mean of 30 eggs/g feces among men and 15.8 eggs/g feces in men and women. The overall prevalence of S. mansoni-infection was 11.8% with a geometric mean excretion of 8.8 eggs/g feces. In addition, the circumoval precipitin test was carried out on 639 sera and 110 (17.2%) were positive, increasing the prevalence in all age groups. Examination of Biomphalaria glabrata snails collected in early 1986 showed 7.8% to be positive for S. mansoni cercariae. Despite the moderate prevalence rates and the low intensity of infection among the human population, we consider Higuey to be an important focus of schistosomiasis in the Dominican Republic. The sensitive coprological and serodiagnostic techniques we employed have helped to identify the age- and sex-specific groups most deserving of treatment in order to reduce transmission of infection and disease prevalence.

Adolescent↗
PubMed2006

Studies on the feeding habits of Lutzomyia (N.) intermedia (Diptera, Psychodidae), vector of cutaneous leishmaniasis in Brazil.

The precipitin test was applied to identify the blood meal sources of Lutzomyia intermedia, collected in two distinct habitats: inside houses and in the peridomicile, in Mesquita, Rio de Janeiro State, Brazil, a transmission area of Leishmania (V.) braziliensis. The following antisera were tested: human, avian, equine, rodent, and opossum. From a total of 370 females analyzed, 128 specimens from the domicile and 59 from the peridomicile reacted with specific antisera. The anthropophily of L. intermedia was confirmed in both habitats; likewise, the feeding of this sand fly species on domestic animals, observed in previous entomological surveys, was confirmed by the strong reactivity with avian, canine, and equine antisera. However, feeding on rodents, mammals frequently found inside and around houses, represents further evidence related to the vector competence of L. intermedia, since synanthropic and sylvatic rodents have been considered a putative reservoir of L. (V.) braziliensis.

Animals↗
PubMed2005

Feeding patterns of Haemagogus janthinomys (Diptera: Culicidae) in different regions of Brazil.

New data on the feeding patterns of Haemagogus (Haemagogus) janthinomys Dyar from different geographical regions of Brazil, by using the precipitin test as the bloodmeal-identifying tool, are presented. The following antisera were used: bird, dog, human, rodent, cattle, horse, and opossum. The origins of 287 bloodmeals were identified, whereas 33 specimens were negative to the antiserums tested. Among the reactive specimens, 174 (60.6%) fed on only one food source, of which 35.1% originated from birds, 19.5% from rodents, 12.6% from humans, 10.3% from cattle, 10.3% from opossums, 7.5% from dogs, and 4.6% from horses. One hundred six (37.0%) mosquitoes fed on two sources, of which the most common combinations were bird + rodent (16.0%), bird + human (10.4%), and horse + human (9.4%). Seven (2.4%) mosquitoes fed on three different hosts. Our results suggest that Hg. janthinomys is more eclectic and opportunist than previously known in relation to its hosts and that such patterns are probably highly adaptive to a temporally and spatially variable environment.

Animals↗
PubMed1972

Prevalence of farmer's lung in Scotland: a pilot survey.

In a survey of the farming population of Orkney, Ayrshire, and East Lothian the prevalence of farmer's lung was estimated at 86 per 1,000 in both Orkney and Ayrshire and 23 per 1,000 in East Lothian. If cases with a negative farmer's lung hay (F.L.H.) precipitin test are excluded these figures are reduced to 43, 36, and nil respectively, but those for Orkney and Ayrshire are still about 20 times higher than any figure previously reported for the prevalence of farmer's lung in Britain.Regional variations in prevalence are probably related both to climatic conditions and to differences in agricultural methods, the latter often being dictated by economic circumstances. Nevertheless the prevalence of farmer's lung could be reduced considerably by the energetic application of preventive measures, backed by financial incentives. The most important of these are efficient drying of hay and cereals before storage, more extensive use of silage, better ventilation of farm buildings, and the introduction of mechanical feeding systems. Individual farmworkers could be taught how to recognize the early symptoms of the disease and encouraged to wear respirators when handling mouldy fodder.

Adult↗
PubMed1976

Immunological evidence for substrate-induced conformational alterations in human carbonic anhydrase B.

The inhibition by specific antibody of carbonic anhydrase B activity towards bicarbonate was uncompetitive (Ki 9.5 X 10(-7) M) whereas that of activity towards p-nitrophenylacetate was mixed-type (Ki 9.2 X 10(-7) M). Differences in the immunological reactivity of the enzyme in the presence of the substrates was documented by quantitative precipitin tests and by the Farr technique. In the presence of bicarbonate, nearly half of the antigenic determinants of the enzyme were altered to such an extent that antibodies directed against these determinants in the native form did not bind. This antibody fraction was separated and shown to react with the native enzyme in different molar ratios than the total antibody population. It produced only a very limited inhibition of the activity towards CO2 and p-nitrophenyl acetate. The immunological reactivity of the enzyme with both the total antibody population and the fraction that is nonreactive in the presence of bicarbonate was identical in the absence of substrates and in the presence of CO2 and p-nitrophenyl acetate. It is suggested that the native enzyme form exhibits enzymatic activity towards CO2 and p-nitrophenyl acetate, whereas in the presence of bicarbonate a "conformational adaptation" is induced.

Acetates↗
PubMed2002

A potential new serotype of Riemerella anatipestifer isolated from ducks in Thailand.

Eighty isolates of Riemerella anatipestifer representing 71 outbreaks of riemerellosis in Thailand between 1994 and 1999 were serotyped using the gel diffusion precipitin test. Based on the precipitation patterns, 25 serological profiles containing one to three antigenic determinants were recognized. Heat-stable antigens of the organism reacted with antisera raised against 16 known serotypes and an untypable strain 698/95. The most prevalent serotype appeared to be serotype 7, followed by serotypes 5, 10, 21 and 1. Further study demonstrated that the untypable strain probably represents a new serotype. Analysis of the polymerase chain reaction-amplified rrs genes for restriction fragment length polymorphisms verified the inclusion of strain 698/95 within the species R. anatipestifer and supported earlier work excluding strain 670/89, which had originally been designated the reference strain of serotype 20. Therefore, it is suggested that the strain 698/95 could be adopted as a replacement for the reference strain of serotype 20. Attention should be paid to strains with multiple antigenic factors as they may be useful for the preparation of vaccines.

Animals↗
PubMed1997

Computer-based analysis of the binding steps in protein complex formation.

Computer models were used to examine whether and under what conditions the multimeric protein complex is inhibited by high concentrations of one of its components-an effect analogous to the prozone phenomenon in precipitin tests. A series of idealized simple "ball-and-stick" structures representing small oligomeric complexes of protein molecules formed by reversible binding reactions were analyzed to determine the binding steps leading to each structure. The equilibrium state of each system was then determined over a range of starting concentrations and Kds and the steady-state concentration of structurally complete oligomer calculated for each situation. A strong inhibitory effect at high concentrations was shown by any protein molecule forming a bridge between two or more separable parts of the complex. By contrast, proteins linked to the outside of the complex by a single bond showed no inhibition whatsoever at any concentration. Nonbridging, multivalent proteins in the body of the complex could show an inhibitory effect or not depending on the structure of the complex and the strength of its bonds. On the basis of this study, we suggest that the prozone phenomenon will occur widely in living cells and that it could be a crucial factor in the regulation of protein complex formation.

Antigen-Antibody Reactions↗
PubMed1969

Quantitative investigations of idiotypic antibodies. I. Analysis of precipitating antibody populations.

Specifically purified anti-p-azobenzoate antibodies of the IgG class from individual rabbits were used to elicit anti-idiotypic antibodies in recipient rabbits. Allotypes of each donor and recipient were matched. When polymerized antibodies were used for immunization, more than 80% of the recipients responded with the formation of antibodies that precipitated the monomeric donor antibody. Percentages of precipitable molecules in the donor antibody population (D) varied from 4 to 56. As little as 4% was readily detectable by the Ouchterlony method or precipitin test. Specificity of the reaction was tested by double diffusion in agar gel against a panel of purified antibenzoate antibodies from 14 heterologous rabbits and, quantitatively, in three systems by measurement of the extent of coprecipitation of heterologous, radiolabeled antibenzoate antibodies. No cross-reactions were observed. Reactions were shown to be attributable to antibenzoate antibodies in the donor serum, and contributions of allotypic reactions were excluded. In three systems investigated quantitatively, and in one studied qualitatively, two recipients of the same donor antibody produced anti-antibody that reacted with essentially the same subfraction of the donor antibody population. The findings that only a portion of the D population is immunogenic, and that the same subfraction is frequently immunogenic in different recipients, suggest that the immunogenic population comprises a limited number of homogeneous groups of antibody molecules. This is supported by the small number of bands usually observed by the Ouchterlony technique. Quantitative methods of analysis should provide an approach to the study of cell populations producing antibodies of a particular idiotype.

Animals↗
PubMed1974

New streptococcal serotypes causing pyoderma and acute glomerulonephritis types 59,60, and 61.

Three new streptococcal M serotypes, types 59, 60, and 61; have been described. They were first isolated from patients with pyoderma and acute glomerulonephritis (AGN), seen during epidemiological studies in Alabama. A possible antigenic relationship between types 59 and 61 was suggested by their T-agglutination reactions; a more specific T antiserum prepared for type 59 was useful in separating these two types, as well as other strains known to share T antigens 11, 12, and 5/27/44. On the basis of precipitin tests, a common antigenic determinant among types 59, 61, and 49 was suggested. This is of interest in view of the relation between these types and AGN. Type 59 has been relatively more widespread in distribution than type 61, but neither have been related to epidemic AGN. Type 60, first identified as "T-4," thus being related to previously described M types which share this antigen, is of great interest in terms of the epidemiology of AGN. Most strains in our collection were recovered from patients with pyoderma and AGN or from their infected siblings. Recently, the type was found to be prevalent among patients with pyoderma and AGN seen in Trinidad. Data reported in relation to these new types further illustrate the dichotomy in M serotypes common to pyoderma and AGN on the one hand and those types found in collections of patients with pharyngitis on the other hand. The high rate of non-M-typable streptococci among pyoderma collections, encountered earlier, is best explained by lack of suitable reference antisera available for prevalent pyoderma serotypes.

Antibodies, Bacterial↗
PubMed1983

Nature of cross-reactivity between Haemophilus influenzae types a and b and Streptococcus pneumoniae types 6A and 6B.

Cross-reactivity between capsular antigens of Haemophilus influenzae types a and b, and Streptococcus pneumoniae types 6A and 6B was studied by means of comparative double diffusion, quantitative precipitin tests and enzyme-linked immunosorbent assay (ELISA). Antisera against whole bacteria were employed. When capsular antigens of S. pneumoniae types 6A and 6B were compared by means of the double diffusion technique, three antigenic determinants were distinguished, two of them being common to the two serotypes. When pneumococcal capsular antigens were compared with H. influenzae capsular antigens, cross-reactive antibodies were detectable only in anti-pneumococcal sera. The heterologous pneumococcal polysaccharide preparation precipitated about 80% of the capsular antibodies in pneumococcal antisera, while heterologous H. influenzae polysaccharide precipitated only about 20-30% of the capsular antibodies in anti-H. influenzae sera. S. pneumoniae polysaccharide precipitated 10-20% of the antibodies in antisera against. H. influenzae, and H. influenzae polysaccharide precipitated about 20-25% of the antibodies in antisera against S. pneumoniae type 6A. Approximately the same degree of cross-reactivity was revealed when ELISA was employed. The absorption study of the antisera with D-ribitol-5-phosphate indicates that this structure is responsible for the cross-reactivity between S. pneumoniae and H. influenzae.

Cross Reactions↗
PubMed1983

Hybridoma antibody-based competitive ELISA in Schistosoma japonicum infection.

A competitive enzyme-linked immunosorbent assay (ELISA) has been developed and compared with the circumoval precipitin test (COPT) for diagnosis of schistosomiasis japonica using Philippine sera. The assay is based on the inhibition, by sera, of the binding of a penicillinase-conjugated hybridoma-derived antibody, I. 134, to a crude Schistosoma japonicum adult worm extract. A change in pH subsequent to addition of the substrate is used as the indicator system. Development of the color change in this assay is relatively slow, a fact which presumably facilitates detection of inhibition by serum. Relative to the COPT, no false positive reactions were obtained and the false negative rate was less than 10%. A wide range of inhibitory titers was obtained using sera in the competitive ELISA similar to that found in a competitive radioimmunoassay using 125I-labeled I. 134. The competitive ELISA will be of more general application for diagnosis of schistosomiasis japonica than the competitive RIA using hybridoma antibodies, and will provide more precise quantitative information than is obtainable in the COPT.

Antibodies↗
PubMed1973

Distribution by serological type of group B streptococci isolated from a variety of clinical material over a five-year period (with special reference to neonatal sepsis and meningitis).

A total of 898 group B streptococci isolated from a wide variety of human clinical sources from July 1967 through June 1972 were typed by the Lancefield precipitin test. Only 11% of the strains were nontypable. Twenty-six percent of the group B strains were from respiratory sources, 22% were from cerebrospinal fluid (CSF) and blood, 13% were from the female genital tract, 12% were urine specimens, and the remaining 27% were from other varied sources. The clinical conditions reported for patients from whom these organisms were isolated included neonatal meningitis and sepsis, pharyngitis, urinary tract and female genital tract infections, and various skin and wound infections. Seventy percent of the CSF and blood cultures from patients with meningitis or sepsis, or both, were type III, whereas the overall percentage of this type was 32%. All but three CSF isolates were from patients under 2 years of age; the distribution of CSF isolates appeared to be the same for both sexes. In contrast, group B streptococci were isolated more frequently from the blood of males than from the blood of females. There were twice as many blood cultures from patients under 2 years of age than from those that were older.

Adolescent↗
PubMed1994

Identification of bloodmeal sources of Lutzomyia spp. in Peru.

Bloodmeal sources of Lutzomyia spp. were determined, using the bloodmeal analysis precipitin test, in Chaute, Lima, Peru, an area endemic for cutaneous leishmaniasis (uta). From April 1990 to May 1991, sandflies were sampled in and around the village houses, with CDC light traps and a Shannon trap with protected human bait, respectively. Overall, 1424 sandflies were collected engorged. In indoor collections, human blood (N = 275) was the most frequent bloodmeal found, followed by cow (171) and cat (152). The most frequent bloodmeals of the flies caught in the Shannon trap collections were from cow (31), man (23) and cat (23). Of the two predominant sandfly species in the area, Lutzomyia peruensis was more anthropophilic than Lu. verrucarum (chi 2 = 14.13, P < 0.001). The sandflies from Chaute appear to be opportunistic feeders; 16 different hosts were identified. There was evidence of bloodmeals from more than one host in each of 151 sandflies, including bloodmeals containing blood from an animal only present within the houses mixed with blood from animals only present in the corrals near the house. Some sandflies must therefore have flown from the corrals to the houses (or vice versa) to take the last bloodmeals before their capture.

Animals↗
PubMed1981

Murine hybridoma-derived antibodies producing circumoval precipitation (COP) reactions with eggs of Schistosoma japonicum.

Of 7 hybridomas which secrete immunoglobulins binding to crude extracts of Schistosoma japonicum adult worms and/or eggs in solid-phase radioimmunoassays (RIAs), 3 gave positive precipitation reactions in the circumoval precipitin test (COPT). The COPT is a simple and inexpensive immunodiagnostic test for schistosomiasis japonica which involves the incubation of a selected batch of S. japonicum eggs with sera from patients and examination for precipitates one or more days later. Using a competitive RIA with an egg antigen extract and a labelled COPT-positive hybridoma ascites fluid, PwF.41-1-3, the surprising observation was made that only one anti-egg antibody specificity appeared to be represented in the series of 3 antibodies (as ascites fluids). Using sera as inhibitors in the competitive RIA, inhibitory activity (presumably antibodies to the target antigenic determinant of PwF.41-1-3) was readily detected in sera from egg-immunized mice and was of relatively high titre in a strain of mouse (C57BL/6) which can be readily sensitized for large granuloma formation around entrapped eggs in the lungs. Negligible inhibitory activity was found in the sera from S. japonicum-infected patients, even with sera from patients with prominent hepatosplenomegaly. The availability of COPT-positive hybridoma antibodies should facilitate isolation of at least one S. japonicum egg antigen involved in COP reactions and perhaps induction of immunopathological immune responses at least in mice.

Animals↗