摘要:

Six sows in the 3rd month of gestation were infected withToxoplasma gondii, four intravenously with the RH strain, two perorally with a porcine strain. Severe disease, characterized by fever, anorexia and dyspnoea, was seen in the animals infected with the RH strain and one sow died on day 4. Mild febrile disease was seen in the porcine strain infections. Parasitaemia andToxoplasmaantibodies became demonstrable in all sows, and at term the sows delivered dead and/or live piglets, the mortality being 50–100 per cent in three RH strain infected litters and 30 per cent in one porcine strain infected litter. At sacrifice,Toxoplasmawas found in the sows infected with the porcine strain but in none of those infected with the RH strain. Non‐viableToxoplasmawas demonstrated histologically in 17 of 35 dead piglets and viableToxoplasmawas isolated from the cord blood of three liveborn piglets. At sacrifice 3–4 weeks after birth,Toxoplasmawas demonstrable in several piglets from both sows infected with the porcine strain but in none of the piglets from sows infected with the RH strain. It is concluded that toxoplasmosis during the 3rd month of pregnancy in swine may cause fetal infection, resulting in death and congenital toxoplasmosis of liveborn piglets. Infection of the fetuses occurs probably during the maternal parasitaemia but horizontal infection i. e. from one litter mate to another, may also take place. There is little chance of isolating viableToxoplasmafrom mummified or macerated fetuses, but non‐viableToxoplasmamay be demonstrated by histological exam

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04279.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Transformation ofN. meningitidisby homologous, genetically marked DNA may be competitively inhibited by non‐marked DNA fromN. sicca, E. coliand calf thymus. It seems that homologous DNA has higher inhibiting activity than the other DNA's tested. The binding by recipient cells of radioactivity from labelled DNA preparations was measured in the transformation system. An uptake of radioactivity from intact DNA which could not be removed by deoxyribonuclease treatment and repeated washings was found with homologous DNA but not with DNA fromE. coli.This irreversible uptake was restricted to competent recipient cells. The uptake was correlated with genetic transfer. The findings indicate that the first step in DNA uptake is a reversible binding to the surface which may depend upon structures common to double‐stranded DNA. The following step appears to be an irreversible phase resulting in deoxyribonuclease insensitivity. This stage seems to be characterized by a specificity for homologous

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04280.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The technique for preparing a large batch ofMycoplasma pneumoniaeantigen for the indirect FAT is described. Some factors relating to reproducibility and specificity are mentioned.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04281.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

In the present study different dye‐to‐protein ratios were used for the conjugation of rabbit anti‐gonococcal globulin with fluorescein isothiocyanate. The conjugates were fractionated on DEAE‐cellulose columns. The fractions obtained were tested for specific and nonspecific reactions by FAT; they were also examined by immunoelectrophoretic analyses and in the gonococcal complement‐fixation test. Specific antibody activity was correlated with the presence of γG‐globulin molecules; the non‐specific staining of leucocytes in FAT was found exclusively in fractions containing heavily‐labelled γG‐globulin molecules. Even when these molecules were removed by chromatography on DEAE‐cellulose, a satisfactory, specific staining of gonococci in direct smears of secre

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04282.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

An account is given of the distribution of 958 strains ofPs. aeruginosaamong 14 O groups, investigated by means of a tube agglutination technique and heat‐treated antigen suspensions. Use has been made of unabsorbed O sera corresponding toHabs12 O groups, an O group 13 fromSandvik'smaterial, and an O group 14 prepared with a strain from the present material. 75 per cent of the strains, which originated chiefly from patients in a hospital environment, could be O group determined. 55 per cent of the strains belonged to O groups 6, 2, 5, 3 and 11. Strains belonging to O groups 2, 5 and 6 were the ones most frequently occurring in a hospital environment. The results showed that strains belonging to O groups 2 and 5 were more frequent than O group 6 strains in a hospital environment and that they colonized more easily than O group 6 strains wounds, urinary tract, ears, pleura and lower respiratory tract, whereas strains belonging to O groups 2 and 5 and O group 6 were equally frequent in the upper respiratory tract and in the large intestine (stools). The frequent occurrence of strains belonging to O groups 2 and 5 in samples from blood and central nervous system can be explained by the finding of these O group strains at sites from wherePs. aeruginosais presumed to advance into the circulation and central nervous syste

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04283.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

We have isolated fractions rich in plasma membranes from baby hamster kidney cells (BHK21) by using a modification of the method ofWallach&Kamat(1966). The specific activity of Na+‐K+‐activated ATPase was 10–20 fold higher in the plasma membranes than in the original homogenate. Antiserum against whole cells gave a strong plasma membrane fluorescence and agglutinated intact BHK21 cells. Quantitative agglutination inhibition studies indicated a 20 fold concentration of the plasma membrane antigens in the isolated plasma membrane fraction. In isolated plasma membrane fractions NADH‐ diaphorase activity was low and succinate dehydrogenase activity not det

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04284.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

In one experiment mice were immunized by repeated oral inoculations withAscaris suumeggs. Immune mice and controls were challenged in 2 ways, viz., orally with eggs and intravenously within vitrohatched second‐stage larvae ofAscaris suum.In a second experiment immune mice and controls were sacrificed 8 hrs after an oral challenge with eggs. It is concluded that the intestine is important for immunity againstAscaris suum, and that the defence mechanism is acting by interfering with the process of hatching and the larval penetration of the gut mucosa. It became evident from Experiment 1 that the large majority of the third‐stage larvae detected in the lungs after oral challenge had not developed from second‐stage larvae in the lungs, but was most likely coming from the

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04285.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The effects of different stimuli of mice upon a following infection withAscaris suumwere elucidated. The results were as follows:—1. Repeated injections with bovine albumin (plusFreund'scomplete adjuvant) significantly increased the resistance against the ascarids.—2. A tendency towards a decreased resistance toAscaris suumwas observed in the mice initially infected withSchistosoma mansoni.—3. The injection with indigo carmine had no apparent effect on the host response.—Possible mechanisms, by which bovine albumin, etc. may increase or decrease resistance, are di

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04286.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The influence of urine osmolality and urinary pH on the survival of spheroplasts fromP. vulgariswas studied in ascending urinary‐tract infections in rabbits treated with penicillin. Spheroplasts were isolated from the urine of three out of fourteen rabbits with hypotonic urines. All three had a urinary pH below 5.5. No spheroplasts were isolated from the hypotonic urines with pH above 5.5 of the other eleven rabbits. However, in this latter group spheroplasts were isolated from the kidney tissue of four rabbits. In the control group consisting of 22 animals spheroplasts were isolated in the urine and in the kidney tissue of 19 and 16 rabbits, respectively. These findings were discussed with regard to urine osmolality, urinary pH and treatment of urinary tract infections with penicilli

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04287.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Organisms common as urinary pathogens were grown in urine and their effect on the urinary pH was followed. Proteus organisms caused a rapid rise in the pH to high levels. When glucose was present in the urine, a slight initial rise was superseeded by a fall of the pH. In mixed infections withP. vulgarisandE. colithe pH did not rise whenE. coliwas dominating but rose at equal concentrations of the two species and whenProteusdominated. These results offer possible explanations why the pH does not always rise in the urine in patients with urinary tract infections withProteus.Possible alternative mechanisms are under investigation.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1970.tb04288.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY