Search PubMed⌕ Search

Biomedical subjects

A Weintraub

Publications and source records attributed to A Weintraub.

At least 127 records · Page 7Linked to original sources
PubMed1982

The role of Bacteroides fragilis in the pathogenesis of acute appendicitis.

The predominant bacteria from 50 inflamed human appendices were isolated. Anaerobic bacteria were isolated more frequently than aerobic bacteria ( 141 versus 96 isolates). E. coli was the most common aerobic genus (47 out of 50 patients). Bacteria belonging to the B. fragilis groups (B. Fragilis, B. ovatus, B. distasonis, B. thetaiotaomicron, B. vulgatus and B. uniformis) were the most frequently isolated anaerobic microorganisms (87 of 141 strains), and B. fragilis predominated within this group (24 out of 87 strains). There were no significant differences in the numbers and types of bacteria found in three patients groups (Group A--19 phlegmonous; Group B--19 gangrenous; and Group C--12 perforative appendicitis cases). Serological investigations of the humoral antibody responses (IFL) against the predominant bacteria in the three patient groups showed that a doubling, or more, of the titer was observed in the following cases: against B. fragilis, 3 out of 8 patients (Group A); 5 out of 7 patients (Group B); and 7 out of 7 patients (Group C). The corresponding figures for E. coli were 4 out of 18, 3 out of 17, and 5 out of 12 patients. Only minor responses against the remaining aerobic and anaerobic isolates were measured. From the bacteriological and immunological results we conclude that (1) the B. fragilis group were the predominant bacteria in diseased appendices; (2) that significant antibody responses were only observed against B. fragilis; (3) that the response increased with the degree of organ destruction and the length of time elapsed from the onset of the symptoms; (4) that B. fragilis is likely to play an important role in the pathogenesis of acute appendicitis, provided that other predisposing factors, such as a deterioration of the blood circulation in the appendiceal wall, are present.

Acute Disease↗
PubMed1980

Nature, type of linkage, quantity, and absolute configuration of (3-hydroxy) fatty acids in lipopolysaccharides from Bacteroides fragilis NCTC 9343 and related strains.

The main fatty acids present in lipopolysaccharides from Bacteroides fragilis NCTC 9343 were identified as 13-methyl-tetradecanoic, D-3-hydroxypentadecanoic, D-3-hydroxyhexadecanoic, D-3-hydroxy-15-methyl-hexadecanoic, and D-3-hydroxyheptadecanoic acids. Of these, 13-methyl-tetradecanoic acid is exclusively ester bound, and 3-hydroxy-15-methyl-hexadecanoic acid is exclusively involved in amide linkage. The other 3-hydroxy fatty acids are both ester and amide bound. All 3-hydroxy fatty acids possess the D configuration, and the 3-hydroxyl group of ester-linked 3-hydroxy fatty acids is not substituted. Lipopolysaccharides of related Bacteroides species (B. thetaiotaomicron, B. ovatus, B. distasonis, and B. vulgatus) showed a fatty acid spectrum with both similar and distinct features compared to that of B. fragilis lipopolysaccharides.

Bacteroides↗
PubMed1979

Encapsulated strains of Bacteroides fragilis in clinical specimens.

Studies were made of the presence of capsules in 294 strains of the Bacteroides fragilis group of bacteria isolated from clinical infections and in 30 strains from the fecal flora using the Indian ink and ruthenium red staining methods. A total of 77% of the B. fragilis strains were encapsulated; higher figures were observed in isolates from blood and wound infections. Of the B. ovatus, B. distasonis, B. vulgatus, B. uniformis, and B. thetaiotaomicron isolates from clinical infections, 17% were encapsulated. The percentage of encapsulated Bacteroides strains isolated from feces was approximately the same as in the strains isolated from clinical infections.

Bacteroides↗
PubMed1979

Identification of Bacteroides fragilis by indirect immunofluorescence.

Rabbit antiserum against live or heat-killed Bacteroides fragilis NCTC 9343 bacteria was titrated against hot phenol water-extracted polysaccharide antigens from five different species of the 'B. fragilis group' of bacteria using an enzyme immunoassay and shown to be specific for the B. fragilis NCTC 9343 polysaccharide. When the antiserum was used in indirect immunofluorescence, 97.1% of 244 B. fragilis strains were correctly identified. Only 8 of the other 312 Bacteroides strains were stained by the anti-B fragilis serum. The 'cross-reactive' Bacteriodes strains all belonged to the "B. fragilis group" of bacteria (i.e., B; distasonis, B. ovatus, B. thetaiotaomicron, B. uniformis, and B. vulgatus). None of the 425 aerobic enteric bacteria representing Salmonella, E. coli, Proteus, Yersinia, Shigella, Klebsiella, Enterobacter, Citrobacter, and Pseudomonas were positive using the anti-B. fragilis serum. Likewise, all the 59 gram-positive strains representing Streptococcus, Bacillus, Peptostreptococcus, Peptococcus, Propionibacterium, Lactobacillus, Eubacterium, and Clostridium did not stain. Our data shows in accordance with other findings [11], that B. fragilis strains possess a species-specific cell envelope antigen(s) which promises to be important for production of antisera, making a rapid identification of the species possible.

Bacteria↗
PubMed1979

The humoral antibody response to Bacteroides fragilis infections in humans.

The humoral antibody response to Bacteroides fragilis infections in humans, with particular reference to ss. fragilis, was studied using an enzyme immunosorbent assay (EIA). Phenol-water extracted polysaccharide fractions (PS) from B. fragilis ss. fragilis, ss. ovatus, ss. distasonis and ss. vulgatus were used as antigens. Antibody titer determinations were done on sera collected from 57 patients where B. fragilis had been cultured and from 50 controls. In patients with septicemia caused by B. fragilis ss. fragilis a significant titer increase (greater than or equal to doubling) against PS from strain 9343 was seen during the course of the illness. In sera from patients with appendicitis, and where B. fragilis was isolated from the appendix, a titer increase against B. fragilis ss. fragilis 9343 was observed for 6 of 17 patients. However, in sera from 9 of the 17 patients a titer increase against B. fragilis ss. ovatus was also seen. No titer increase was observed in sera from most of the patients with salpingitis where B. fragilis had been isolated. In sera from 10 patients with Crohn's disease the median antibody titer against all four B. fragilis antigens was slightly higher than in sera from the controls. The median antibody titer against B. fragilis ss. ovatus was, however, significantly higher. Our experience is that a humoral antibody response against B. fragilis ss. fragilis can be expected in patients where the organism is isolated from blood. In diseases like appendicitis and salpingitis titer increases are less common. When they occur they are not necessarily directed against ss. fragilis only but are as frequent against ss. ovatus. Titer increases against ss. vulgatus and ss. distasonis are also seen. This raises the question if the observed titer increases are a consequence of a specific pathogenic role of B. fragilis in these infections, or if they merely represent the result of an antigenic stimulus as a result of an increased permeability of the mucosal barriers caused by inflammation and/or surgical manipulation.

Antibodies, Bacterial↗
PubMed1977

Secondary syphilis revealed by rheumatic complaints.

Six patients (five men and one woman) are described, who consulted rheumatologists with varied rheumatic complaints: four had subacute synovitis with effusion, frequently associated with vague arthralgias; and five of the patients had back pain which was more severe at rest. Most of the patients had some clinical signs of secondary syphilis, such as roseola, loss of hair, or lymphadenopathy, and their serological reactions for lues were strongly positive. Since no other cause for these rheumatic complaints could be found, secondary syphilis was considered responsible for them. In all cases the rheumatic complaints cleared with specific treatment.

Adult↗
PubMedDate not supplied

Serum antibody response to Bacteroides fragilis in experimental sinusitis.

Maxillary sinusitis was induced in New Zealand white rabbits by local inoculation of 10(6) colony-forming units of Bacteroides fragilis NCTC 9343, and the serum IgG, IgA and IgM antibody responses to cell wall antigens were studied. Prior to inoculation, and one, two, three and four weeks after induction, serum samples were obtained and analysed for antibodies to the lipopolysaccharide and the capsular polysaccharide. Capsular polysaccharide from B. fragilis ATCC 23745 was used as control. The rise in IgG activity against NCTC 9343 capsular polysaccharide and lipopolysaccharide was most marked and sustained throughout the four weeks. The increases in IgA concentration were moderate and sometimes transient, and a more pronounced IgA increase was seen with IFA than with EIA. The IgM peak levels were weak and usually declined within two to three weeks. The development of antibody to the lipopolysaccharide was similar to that of the NCTC 9343 capsular polysaccharide antibodies, though somewhat delayed in time. No significant increase in antibody to the control capsular polysaccharide was seen.

Animals↗
PubMedDate not supplied

Intracardiac echocardiographic imaging of cardiac abnormalities, ischemic myocardial dysfunction, and myocardial perfusion: studies with a 10 MHz ultrasound catheter.

Intracardiac echocardiography (ICE), an echocardiographic examination from within the heart itself, has been proposed as a new modality for cardiac imaging. A major shortcoming has been the limited depth of field provided by previously available devices. We used 10 MHz catheters for ICE to determine if this lower frequency would allow for greater display of cardiac anatomy. We performed ICE in seven animals; myocardial ischemia was induced in three. With the imaging catheter in the right atrium, all four cardiac chambers and valves could be imaged. Advancing the transducer into the right ventricle allowed for short-axis images of the left ventricle. Coronary perfusion territories and segmental wall motion abnormalities could be observed. We then performed ICE in six patients by advancing the catheter into the right side of the heart percutaneously. Structures of the right side of the heart, the mitral valve, aortic valve, left atrium, and portions of the left ventricle, were visualized. Congenital and acquired abnormalities could be identified. There were no complications. We conclude that ICE with 10F, 10 MHz ultrasound catheters allows for expanded imaging capabilities because of the increased depth of field. With this imaging modality, congenital and acquired abnormalities as well as myocardial ischemia can be detected.

Adult↗
PubMedDate not supplied

Structure-activity relationships in lipopolysaccharides of Bacteroides fragilis.

The endotoxic activity of lipopolysaccharide (LPS) extracted from the envelope of Bacteroides fragilis is low compared with that of LPS from Escherichia coli, Salmonella, and other Enterobacteriaceae. Thus, pyrogenicity, the ability to prepare for or provoke the local Shwartzman reaction, and the ability to induce the production of interleukin 1 are reduced by 100- to 1,000-fold. Structural analyses of characterized B. fragilis LPS have shown that its lipid A is composed of a beta 1,6-linked D-glucosamine disaccharide that has the following properties: (1) a phosphate group on C1 of the reducing amino sugar, (2) amide- and ester-linked 3-hydroxylated branched and nonbranched long-chain (C15-C17) fatty acids, (3) an average of five fatty acids per glucosamine disaccharide, and (4) the core and O-antigenic saccharide chain linked to C6 of the nonreducing glucosamine residue. Although structurally similar to lipid A of E. coli, the lipid A of B. fragilis differs by its lack of the phosphate group on C4 of the nonreducing amino sugar and by the presence of fewer and different fatty acids. These differences explain the low endotoxic activity of B. fragilis LPS. The core and O-antigenic chain are linked to lipid A via a phosphorylated 2-keto-3-deoxyoctonate (KDO) residue. The saccharide chain is short and is composed of L-rhamnose, D-glucose, and D-galactose, with the O-antigenic specificity determined by a beta 1,6-linked D-galactose oligomer. This O-antigenic specificity was present in 14 of 17 strains of B. fragilis that were investigated.

Animals↗