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Biomedical subjects

A White

Publications and source records attributed to A White.

At least 433 records · Page 24Linked to original sources
PubMed1980

Isolation of a phosphorylcholine-containing component from the turbot tapeworm, Bothriocephalus scorpii (Müller), and its reaction with C-reactive protein.

A fraction isolated by electrofocusing (pI 4.2) from a saline extract of the turbot parasite, Bothriocephalus scorpii, contained choline and precipitated with a teleost C-reactive protein (CRP) and a phosphorylcholine-binding Balb/c mouse myeloma protein, TEPC-15. Non-dialysable products released from cultured tapeworms also precipitated with the phosphorylcholine-specific precipitins. Ca2+ was required for precipitation with CRP and immunodiffusion lines were confluent with pneumococcal C-polysaccharide and a fungal C substance. Intradermal injection of the phosphorylcholine-containing fraction caused an immediate erythema reaction in all mature turbot tested. The skin reaction is though to be related to the amount of circulating CRP and this protein was present in sera fro all nature turbot giving a positive skin response. There is no evidence for CRP being toxic to the tapeworms and the possibility is discussed that the worms exploit the host CRP for their own survival.

Animals↗
PubMed1980

Properties of galactosyltransferase-enriched vesicles of Golgi membranes from lactating-rat mammary gland.

Lactose was synthesised within the lumen of purified Golgi membrane vesicles, prepared from lactating rat mammary gland, from externally added glucose and UDP-galactose. An apparent Km of 1.5 mM was shown towards glucose at anomeric equilibrium, but only beta-glucose was utilised. Two apparent Km values, about 17 micro M and 112 micro M, were shown towards UDP-galactose. 5-D-Thioglucose, 6-deoxy-D-glucose and 6-deoxy-6-chloro-D-glucose were alternative substrates, acquiring alpha-lactalbumin dependence when the vesicles were lysed with detergent. Substrates independent of alpha-lactalbumin, or inhibited by it, included a wide range of N-acylated glucosamines as well as phenyl-beta-glucoside. The galactosylation of these by vesicle preparations could be ascribed to a proportion of leaky vesicles. Suitably low concentrations of Triton X-100 activated lactose synthesis by intact vesicles, indicating the membrane as a rate-limiting feature of the system.

Animals↗
PubMed1980

Thermodissociation of staphylococcal immune complexes and detection of staphylococcal antigen in serum from patients with Staphylococcus aureus bacteremia.

We describe a simple and rapid method to dissociate antigen-antibody complexes to allow antigen detection by radioimmunoassay. Immunoglobulins and immune complexes were precipitated from serum in 50%-saturated ammonium sulfate. The precipitate was dissolved in distilled water and heated at 90 degrees C for 15 min to free the antigen and denature the antibody irreversibly. With this treatment, the sensitivity for detecting staphylococcal antigen added to human serum improved greater than or equal to 16-fold and was similar to the sensitivity in buffer. After intravenous injection of antigen into a rabbit with high levels of staphylococcal antibodies, antigen was detected only after thermodissociation. Also, in 4 of 26 patients with Staphylococcus aureus bacteremia, circulating antigen was detected after thermodissociation. Thermodissociation of immune complexes is a simple, rapid method and should be useful for detecting other heat-stable antigens.

Antibodies, Bacterial↗
PubMed1980

Detection of Pseudomonas aeruginosa antigenemia in granulocytopenic rabbits by radiommunoassay.

We assessed the ability of a solid-phase radioimmunoassay, modified to allow antigen detection in serum, to detect circulating antigens in granulocytopenic rabbits with Pseudomonas aeruginosa bacteremia. In vitro experiments with Pseudomonas lipopolysaccharide indicated that treatment of serum-lipopolysaccharide mixtures with heat, chloroform, or heparin improved the sensitivity for detecting lipopolysaccharide 8- to 16-fold. Chloroform treatment permitted antigen detection in serum or plasma of bacteremic rabbits in which antigen could be detected poorly or not at all in untreated specimens. However, chloroform-treated specimens occasionally caused dissolution of plastic tubes, resulting in nonspecific binding of 125I-labeled anti-Pseudomonas immunoglobulin G. Heating sera at 56 degree C for 30 min improved antigen detection both in both in lipopolysaccharide-serum mixtures and in bacteremic rabbits. Antigen was detected in the heated serum or plasma of 20% of 20 culture-positive granulocytopenic rabbits, none of 15 culture-negative granulocytopenic rabbits, and none of 38 normal rabbits. Antigen was detected in none of 15 rabbits with 2 to 300 colony-forming units of P. aeruginosa per ml of blood and in 4 of 5 rabbits with > 10(3) colony-forming units per ml. We conclude that circulating antigens are present in the blood of rabbits with high-level P. aeruginosa bacteremia and that these antigens can be detected by solid-phase radioimmunoassay. Further improvements in assay sensitivity will be required to detect antigens, if present, in animals with lower levels of P. aeruginosa bacteremia.

Agranulocytosis↗
PubMed1979

Serologic diagnosis of access device-related staphylococcal bacteremia.

Staphylococcal bacteremia occurs frequently in patients undergoing long-term hemodialysis (dialysis patients). Although such bacteremia is frequently uncomplicated, it may be associated with endocarditis, metastatic infection or suppuration at the access site requiring excision of the access device for control of the infection (complicated bacteremia). To distinguish patients with uncomplicated bacteremia from those with complications, we measured staphylococcal teichoic acid antibodies by agar-gel diffusion and immunoglobulin G (IgG) antibodies by radioimmunoassay in 18 patients with staphylococcal bacteremia undergoing long-term hemodialysis. Although teichoic acid antibodies were not detected in five patients with uncomplicated bacteremia, they were observed in only three of 13 patients with complicated bacteremia. IgG staphylococcal antibodies were present in 10 of 13 patients with complicated bacteremia compared to none of five patients with uncomplicated bacteremia compared to none of five patients with uncomplicated bacteremia (p less than 0.05). Thus, radioimmunoassay was spuerior to agar-gel diffusion in identifying dialysis patients with complicated bacteremia. In patients with increased concentrations of IgG staphylococcal antibodies by radioimmunoassay, the diagnosis of endocarditis, metastatic infection and suppuration at the access site should be considered. Prolonged antibiotic therapy and/or operative removal of the access device may be necessary.

Antibodies, Bacterial↗
PubMed1979

Circulating staphylococcal antigen in humans and immune rabbits with endocarditis due to Staphylococcus aureus: inhibition of detection by preexisting antibodies.

A radioimmunoassay for staphylococcal antigen that had detected antigenemia in each of 12 nonimmune rabbits with staphylococcal endocarditis detected antigen in sera from one of nine humans and two of eight immune rabbits with Staphylococcus aureus endocarditis. Staphylococcal antigens could be detected at concentrations as low as 0.78 microgram/ml when diluted in normal rabbit serum, compared with 6.25 microgram/ml when diluted in normal human serum and greater than 25 microgram/ml when diluted in immune rabbit or human serum. Low titers of staphylococcal antibody were found in normal rabbit serum compared with immune rabbit and normal or immune human sera. Detection of staphylococcal antigen was inhibited when the antigen was diluted in the IgG and IgM fractions, but not in the albumin fraction, of normal human serum. This study demonstrated that antigenemia can be detected infrequently in patients and immune rabbits with staphylococcal endocarditis; staphylococcal antibodies inhibit detection of antigen, presumably through formation of immune complexes.

Animals↗
PubMed1979

Inhibitory effect of heat-labile serum factors on detection of staphylococcal, pseudomonas, and hepatitis B surface antigens by solid-phase radioimmunoassay.

Specific antibodies have previously been found to impair detection of staphylococcal antigen by solid-phase radioimmunoassay. The inhibitory effect of heat-labile serum factors on the detection of antigen is now described. Heating of serum at 56 C for 30 min prior to addition of antigens of Pseudomonas aeruginosa or Staphylococcus aureus improved sensitivity by eight- to 32-fold. Heating was less effective when performed after addition of antigen. Treatment with zymosan reduced the inhibitory effect of serum, although less effectively than did preheating. Antigen in buffer was detected with 16 times less sensitivity in antibody-coated tubes exposed to fresh serum than in tubes exposed to heated serum. These findings suggest that complement factors can interact with antibody in coated tubes and at least some antigens and thereby inhibit detection of antigen. The finding that heat treatment improved the sensitivity of Ausria II -125 (Abbott Laboratories, North Chicago, Illinois) for hepatitis B surface antigen is of potential immediate clinical applicability.

Animals↗
PubMed1979

Cephaloridine prophylaxis in resection of the large intestine.

A controlled prospective clinical trial of cephaloridine chemoprophylaxis in resection of the large intestine was undertaken between 1974 and 1978. Data were available on 159 of 177 unselected patients. All were operated on by one surgeon. Three groups were studied: intraabdominal resection and anastomosis (102 patients); pullthrough resection and anastomosis (30 patients): and resection, with colostomy or ileostomy, without anastomosis (27 patients). In the total patient series cephaloridine reduced wound infection from 38.3% to 15.4% (P less than 0.003). There was no significant decrease in intraabdominal infection. In the group of patients undergoing intraabdominal resection and anastomosis the would infection rate was reduced from 40.0% to 14.9% (P less than 0.01). Cephaloridine reduced wound infection from 50.0% to 21.4% (P = 0.05) in those patients in whom drainage tubes were inserted. A decrease in the incidence of faecal fistula from 10.9% to 4.3% was not significant. Wound infections were not reduced significantly after pullthrough excisions or resections without anastomosis. The results support the routine prophylactic use of cephalosporins in patients undergoing intraabdominal resection of the large intestine with anastomosis.

Cephaloridine↗
PubMed1979

Teichoic acid antibody determination by agar-gel diffusion: effect of using dilute antigen preparations.

Because the reported frequency of teichoic acid precipitins in controls and various patient groups has varied considerably among laboratories, we studied the effect of using various concentrations of staphylococcal extracts in agar-gel diffusion tests for teichoic acid antibodies. Of 25 normal sera, only 1 was positive against an undiluted extract, but 4 were positive against a 16-fold-diluted extract. Of nine sera from patients with staphylococcal bacteremia, two were positive at a higher titer against the diluted extract. A false-positive serum against the undiluted extract had a twofold titer increase against the diluted extract. Because human immune serum globulin is generally used as a positive teichoic acid antibody control, the variability of five different lots was studied. Three lots ahd teichoic acid antibody titers of 1:4, whereas one each had titers of 1:2 and 1:8. Based on this study, we feel that staphylococcal extracts should not be diluted. If immune serum globulins are used to determine the adequacy of ultrasonic extracts, newly acquired globulin lots should be standarized against an ultrasonic extract of proven sensitivity and specificity.

Antibodies, Bacterial↗
PubMed1979

Rapid diagnosis of Pseudomonas aeruginosa urinary tract infections by radioimmunoassay.

A solid-phase radioimmunoassay designed to detect serotype 6 Pseudomonas aeruginosa antigens was evaluated for its ability to rapidly diagnose urinary tract infections. Twelve P. aeruginosa serotypes were easily differentiated in the assay from eight other gram-negative bacterial species. During log-phase growth, the assay detected antigens in culture when approximately 10(6) or more serotype 6 P. aeruginosa organisms were present. Both cell-associated and solubilized antigens were detected. The assay detected antigens in 13 of 17 urine specimens which grew greater than 10(5) P. aeruginosa, 3 of 38 which grew other gram-negative rods, and none of 83 with no growth. Two of the three positive specimens from the other gram-negative rod group probably also contained P. aeruginosa. No preincubation of the urine specimens was required, and results were available within 2.5 h. The assay represents an improvement over other procedures for rapidly diagnosing urinary tract infections in that it allows diagnosis by species and should be adaptable to semiautomation.

Antigens, Bacterial↗
PubMed1979

Apnea recordings of healthy infants at 40, 44, and 52 weeks postconception.

A total of 129 recordings of the respiratory activity of 46 normal full-term infants were obtained continuously for 24 hours in the hospital nursery at 3 days of life and in the home environment at 4 weeks and 12 weeks after birth. The pediatric pneumogram (PPG) technique, an impedance method, was used. Pneumogram data over longer than 16 hours was obtained on 77% of infants monitored. No infants experienced apnea longer than 15 seconds in duration at 40 and 44 weeks postconception, or greater than 11 seconds at 52 weeks postconception. Twenty-four hour plots of hourly apnea frequency revealed a marked variability, with evidence of clustering of apneic episodes during periods of reported sleep. Longest apnea time and hourly frequency of apneic episodes were highly correlated.

Apnea↗